UNEP PCFV Regulatory Toolkit


The Partnership for Clean Fuels and Vehicles (PCFV) has been working with developing and transitional countries to reduce vehicular air pollution through the promotion of cleaner fuels and vehicles. This regulatory toolkit is part of that ongoing campaign and is meant to introduce the need for a systems approach to vehicle emission reduction. A systems approach matches fuels and vehicle improvements - to move towards tighter vehicle emissions regulations.

This toolkit will support developing and transitional countries to introduce requirements for 50 ppm and below sulfur fuels; produce or import lower emitting and more efficient vehicle technologies; establish vehicle emissions control roadmaps; and ultimately improve air quality and human health in these countries. The toolkit will show by examples how to build a regulatory strategy, establish enabling legislation and regulatory standards, and set up enforcement mechanisms. The toolkit will also use specific case examples to illustrate how countries can integrate cleaner fuels and vehicles emission standards. Many developing and transitional countries - through support of the PCFV - have completed the phase-out of leaded petrol, followed by the adoption of targets and roadmaps to introduce lower sulfur fuels. Most of these countries however have yet to introduce vehicle emission standards as shown in the map below. Euro 3 vehicle emission standards will require 150 ppm sulfur in petrol and 350 ppm sulfur in diesel in order to meet emissions limit.

Vehicle Emission Standards 2015
Vehicle Emission Standards April 2015. Source: PCFV Secretariat

One of the most important lessons learned in the approximately 50-year history of vehicle pollution control worldwide is that vehicles and fuels must be treated as a system. Improvements in vehicles and fuels must proceed in parallel if significant improvements in vehicle related air pollution are to occur. A program that focuses on vehicles alone is doomed to failure; conversely, a program designed to improve fuel quality alone also will not be successful.

A second important lesson is that a program that focuses on improving vehicles and fuels as a system can be successful. Many countries are following the EU system which lays out a clear roadmap with explicit links between vehicle emissions standards and the associated technologies with appropriate fuel parameters and specifications needed to optimize emissions performance.

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“Auto/Oil Air Quality Improvement Research Program, Final Report”, January 1997. The program consisted of two stages: the first stage called JCAP I commenced in FY 1997 and terminated in FY 2001; the second called JCAP II commenced in FY 2002 and continued until 2007 to provide a further development of the research activities of JCAP I.

Fuels and Vehicles as a System

Gasoline Vehicles and Fuels
Diesel Vehicles and Fuels

Gasoline Vehicles and Fuels

Gasoline is a complex mixture of volatile hydrocarbons used as a fuel in internal combustion engines. The emissions of greatest concern from gasoline-fuelled vehicles are Carbon Monoxide (CO), Hydrocarbons (HC), Nitrogen Oxides (NOx), Particulate Matter (PM) and certain toxic hydrocarbons such as benzene, formaldehyde, acetaldehyde, and 1,3-butadiene. Each of these can be influenced by the composition of the gasoline used by the vehicle. The most important characteristics of gasoline with regard to its impact on emissions are sulfur concentration, volatility (typically expressed as vapor pressure), aromatics, olefins, oxygenates, and benzene level.

Impact of Gasoline Composition on Vehicle Emissions

summarizes the impacts of various gasoline fuel qualities on emissions from light duty gasoline vehicles as a function of European emissions standards.

Two- and Three-Wheeled Vehicles

Most two- and three-wheeled vehicles currently used are not equipped with catalytic converters to control emissions. Therefore it would seem that the impact of the various fuels parameters is similar to those from pre Euro 1 cars. Where Euro 3 limits have been introduced however, vehicles are impacted by sulfur and lead in a manner similar to Euro 1 and 2 gasoline fueled cars. For two- and three-wheeled vehicles equipped with 2-stroke engines, the amount and quality of the lubricating oil is probably more important for emissions than fuel quality but this technology is rapidly being phased out in most countries. This is fortunate as 2-stroke engines have very high PM emissions relative to 4-stroke engines.

summarizes the Impact of Gasoline Composition on Emissions from Motorcycles.

Diesel Vehicles and Fuels

Diesel fuel is a complex mixture of hydrocarbons with the main groups being paraffins, napthenes and aromatics. Organic sulfur is also naturally present. The actual properties of commercial automotive diesel depend on the refining practices employed and the nature of the crude oils from which the fuel is produced. The quality and composition of diesel fuel can significantly influence emissions from diesel engines.

Diesels emit high levels of oxides of nitrogen and particulates. Modifying engine parameters to simultaneously reduce both NOx and Particulates (PM) is difficult and limited since the optimal settings for one pollutant frequently increases emissions of the other and vice-versa. Achieving very low levels of NOx and PM therefore require exhaust treatment. Reformulated diesel fuels can effectively reduce oxides of nitrogen and particulate emissions from all diesel vehicles. These fuels have reduced sulfur, reduced aromatics, and increased Cetane Number. To reduce PM and NOx emissions from a diesel engine, the most important fuel characteristic is sulfur because sulfur contributes directly to PM emissions and high sulfur levels preclude the use of or impair the performance of the most effective PM and NOx control technologies.

summarizes the impact of diesel fuel quality on emissions from light duty diesel vehicles and the impact on heavy duty diesel vehicles emissions.

Traditionally gasoline fueled vehicles have not been a significant source of PM but newly emerging gasoline direct injection technologies can emit much higher levels of particulate. Other than Japan, the United States and Canada, most countries follow the European fuels and vehicles roadmap. “Development of a Predictive Model for Gasoline Vehicle Particulate Matter Emissions,” SAE Int. J. Fuels Lubr. 3(2):610-622, 2010, doi: 10.4271/2010-01-2115. Author(s): Koichiro Aikawa - Honda R&D Co Ltd, Takayuki Sakurai - Honda R&D Co Ltd, Jeff J. Jetter - Honda R&D Americas Inc.

Why The World is Moving Toward Very Low Sulfur Fuels

A.     Sulfur Levels
B.     Concerns About Sulfur
C.     Lessons Learnt


It is now understood that sulfur content must be reduced to very low levels if the maximum benefits are to be achieved by the most advanced technologies used with combustion engines today. When crude oil is processed into gasoline and diesel fuel in the refinery, some sulfur finds its way into the fuel. The higher the density of the crude oil, the more difficult it is to remove the sulfur. Depending on the crude oil used and the refinery configuration, sulfur levels in gasoline can be anywhere from 10 to as high as 1000 ppm or more, and in diesel fuel it can be from 10 or lower to more than 10,000 ppm. Below is a global map of the current sulfur levels in diesel fuels.

Diesel Fuel Sulphur Levels: Global Status 2015.  Source: PCFV Secretariat
Diesel Fuel Sulphur Levels: Global Status April 2015. Source: PCFV Secretariat

Concerns About Sulfur

There are four main reasons why countries are concerned about the sulfur content of fuels:

  1. Health Impacts
  2. Environmental Effects
  3. Potential Damage to Engines
  4. Degradation of Technologies Needed to Reduce Vehicle Emissions

Motor vehicles can emit large quantities of CO, HC, NOx, and such toxic substances as benzene, formaldehyde, acetaldehyde, 1,3,butadiene and PM. Depending on fuel composition, they can also emit significant amounts of sulfur oxides (SOx) and lead. Each of these, along with secondary by-products such as ozone (O3), can cause serious adverse effects on health and the environment.

Particulate Matter
Particulate Matter

Fine particles are produced primarily by combustion processes but also through transformations of gaseous emissions (e.g., SOx, NOx and VOCs) in the atmosphere. Thus, PM2.5 includes a complex mixture of different pollutants including sulfates, nitrates, organic compounds, elemental carbon and metal (including toxic heavy metal) compounds. These particles can remain in the atmosphere for days to weeks and travel through the atmosphere hundreds to thousands of kilometers.

The WHO Air Quality Guidelines for PM are:
  • PM2.5: 10 µg/m3 annual mean, 25 µg/m3 24-hour mean
  • PM10: 20 µg/m3 annual mean, 50 µg/m3 24-hour mean

Health effects associated with short-term exposures (hours to days) to ambient PM include premature mortality, increased hospital admissions, heart and lung diseases, increased cough, adverse lower- respiratory symptoms, decrements in lung function and changes in heart rate rhythm and other cardiac effects. Studies examining populations exposed to different levels of air pollution over a number of years show associations between long-term exposure to ambient PM2.5 and both total and cardiovascular and respiratory mortality.

The Global Burden of Disease Study 2010 (GBD 2010) is the largest-ever systematic effort to describe the global distribution and causes of a wide array of major diseases, injuries, and health risk factors. The results show that outdoor air pollution, primarily PM2.5 is responsible for over 3.2 million premature deaths each year. It is clear that air pollution is an extremely serious and widespread problem which requires strong action.


Ground-level ozone pollution is formed by the reaction of VOCs and NOx in the atmosphere in the presence of heat and sunlight.

The health and welfare effects of ozone are well documented. Ozone can irritate the respiratory system, causing coughing, throat irritation, and/ or uncomfortable sensation in the chest. It can reduce lung function and make it more difficult to breathe deeply, and breathing may become more rapid and shallow than normal, thereby limiting a person’s activity. Ozone can also aggravate asthma, leading to more asthma attacks that require a doctor’s attention and/or the use of additional medication. People who are more susceptible to effects associated with exposure to ozone include children, the elderly, and individuals with respiratory disease such as asthma.

Those with greater exposures to ozone, for instance due to time spent outdoors (e.g. children and outdoor workers), are also of concern, even with short-term exposure under current ground-level ozone levels. Current research suggests that the actual ozone concentration threshold for mortality may be lower than current public health standards, and research on this topic is ongoing. In light of variation of response of different individuals to ambient ozone levels, the WHO recommends that air quality guidelines be set at the level of Ozone: 100 µg/m3 for daily maximum 8-hour mean

Nitrogen Dioxide
Nitrogen Dioxide

NO2 has been associated with adverse health effects even when the annual average NO2 concentration complied with the WHO-2000 annual guideline value of 40 µg/m3. Also some indoor studies suggest effects on respiratory symptoms among infants at concentrations below 40 µg/m3. Together these results support a lowering of the annual NO2 guideline value. The current scientific literature, therefore, has not accumulated sufficient evidence to change the WHO 2000 guideline value of 40 µg/m3 for annual mean NO2 concentrations.

Short-term experimental human toxicology studies show acute health effects at levels higher than 500 µg/m3, and one meta-analysis has indicated effects at levels exceeding 200 µg/m3. The current scientific literature has not accumulated evidence to change from the WHO 2000 guideline value of 200 µg/m3 for 1-hour NO2 concentration.

In conclusion, the WHO guideline values remain unchanged at the following levels:
  • NO2 concentration: 40 µg/m3 for annual mean
  • NO2 concentration: 200 µg/m3 for 1-hour mean

Evidence from recent studies is "sufficient to infer a likely causal relationship" between short-term exposure to NO2 and adverse effects on the respiratory system. According to a draft Environmental Protection Agency risk assessment, a 30-minute exposure to NO2 concentrations between 0.2 ppm and 0.3 ppm has been shown to irritate airways in asthmatics. Children, whose lung function continues to develop into adolescence, and those over the age of 65 are also particularly susceptible to NO2 exposure. The risk assessment also identified as an at-risk group those whose jobs require significant periods of driving. Mean nitrogen dioxide levels inside vehicles are often two to three times the outdoor concentrations.

Sulfur Dioxide
Sulfur Dioxide

Controlled short-term exposure studies with exercising asthmatics indicate that some individuals experience changes in pulmonary function and respiratory symptoms after periods of exposure as short as 10 minutes. Based on this evidence, it is recommended by WHO that a value of 500 µg/m3 should not be exceeded over averaging periods of 10 minutes. Because exposure to sharp peaks depends on the nature of local sources and meteorological conditions, no single factor can be applied to this value in order to estimate corresponding guideline values over somewhat longer periods, such as an hour.

For longer-term exposure, there is still considerable uncertainty as to whether sulfur dioxide is the pollutant responsible for the observed adverse effects or, rather, a surrogate for ultra-fine particles or some other correlated substance. For example, in Germany and the Netherlands a strong reduction of SO2 concentrations occurred over a decade. Although mortality also decreased with time, the association of SO2 and mortality was judged to not be causal and was attributed to a similar time trend of a different pollutant (PM). In consideration of:

  1. The uncertainty of SO2 in causality
  2. The practical difficulty of reaching levels that are certain to be associated with no effects
  3. The need to provide greater degrees of protection than those provided by the guidelines published in 2000
and assuming that reduction in exposure to a causal and correlated substance is achieved by reducing sulfur dioxide concentrations, then there is a basis for revising the 24 hour guideline downward for sulfur dioxide, and the following guideline is recommended as a prudent precautionary level:
Sulfur dioxide: 20 µg/m3 for 24-hour mean.
500 µg/m3 for 10-minute mean (unchanged)
The WHO has determined that an annual guideline is not needed, since compliance with the 24-hour level will assure low levels for the annual average.

Carbon Monoxide

Carbon monoxide (CO) - an odorless, invisible gas created when fuels containing carbon are burned incompletely – also poses a serious threat to human health. Fetuses and persons afflicted with heart disease are especially at risk. Numerous studies in humans and animals have demonstrated that individuals with weak hearts are placed under additional strain by the presence of excess CO in the blood. Some epidemiologic studies have found relationships between increased CO levels and increases in mortality and morbidity.

Healthy individuals also are affected, but only at higher levels. Exposure to elevated CO levels is associated with impairment of visual perception, work capacity, manual dexterity, learning ability and performance of complex tasks.

Air Toxics
Air toxins from exhaust fumes

People experience elevated risk of cancer and other noncancerous health effects from exposure to air toxics. Mobile sources are a major source of this exposure. According to the US National Air Toxic Assessment (NATA) for 1999, mobile sources were responsible for 44 percent of outdoor toxic emissions and almost 50 percent of the cancer risk among the 133 pollutants quantitatively assessed. It is important to note that NATA estimates of noncancerous hazard do not include the adverse health effects associated with particulate matter. Benzene is the largest contributor to cancer risk of all the assessed pollutants and mobile sources were responsible for about 68 percent of all benzene emissions in 1999.

There are a number of public welfare effects associated with the presence of ozone and PM2.5 in the ambient air including the impact of PM2.5 on visibility and materials and the impact of ozone on plants, including trees, agronomic crops and urban ornamentals.

Smog in Beijing

Visibility can be defined as the degree to which the atmosphere is transparent to visible light. Visibility impairment manifests in two principal ways: as local visibility impairment and as regional haze. Local visibility impairment may take the form of a localized plume, a band or layer of discoloration appearing well above the terrain as a result of complex local meteorological conditions. Alternatively, local visibility impairment may manifest as an urban haze. This urban haze is largely caused by emissions from multiple sources in the urban areas and is not typically attributable to only one nearby source or to long-range transport. The second type of visibility impairment, regional haze, usually results from multiple pollution sources spread over a large geographic region. Regional haze can impair visibility in large regions and across states.

Acid Deposition
Acid Deposition

Acid deposition, or acid rain as it is commonly known, occurs when NOx and SO2 react in the atmosphere with water, oxygen and oxidants to form various acidic compounds that later fall to earth in the form of precipitation or dry deposition of acidic particles. It contributes to damage of trees at high elevations and in extreme cases may cause lakes and streams to become so acidic that they cannot support aquatic life. In addition, acid deposition accelerates the decay of building materials and paints, including irreplaceable buildings, statues, and sculptures that are part of a nation’s cultural heritage.

Nitrogen oxides have also been found to contribute to ocean acidification, thereby amplifying one of the many deleterious impacts of climate change. Approximately one third of all nitrogen oxide emissions end up in the oceans. The impact of these emissions on acidification is intensely felt in specific, vulnerable areas; in some areas it can be as high as 10 to 50 percent of the impact of carbon dioxide. The hardest hit areas are likely to be those directly around the release site, so these emissions are especially significant in and around coastal waters.

Eutrophication and Nitrification
a shallow eutrophic lake

Nitrogen oxides emitted by vehicles and other sources into the air can deposit to water bodies and contribute to eutrophication and nitrification. Eutrophication is the accelerated production of organic matter, particularly algae, in a water body. Nitrogen deposition contributes to eutrophication of watersheds, particularly in aquatic systems where atmospheric deposition of nitrogen represents a significant portion of total nitrogen loadings. This increased growth can cause numerous adverse ecological effects and economic impacts, including nuisance algal blooms, dieback of underwater plants due to reduced light penetration, and toxic plankton blooms. Algal and plankton blooms can also reduce the level of dissolved oxygen, which can adversely affect fish and shellfish populations. In recent decades, human activities have greatly accelerated nutrient impacts, such as nitrogen and phosphorus, causing excessive growth of algae and leading to degraded water quality and associated impairment of freshwater and estuarine resources for human uses.

Severe and persistent eutrophication often directly impacts human activities. For example, losses in a nation’s fishery resources may be directly caused by fish kills associated with low dissolved oxygen and toxic blooms. Declines in tourism occur when low dissolved oxygen causes noxious smells and floating mats of algal blooms create unfavorable aesthetic conditions. Risks to human health increase when the toxins from algal blooms accumulate in edible fish and shellfish, and when toxins become airborne, causing respiratory problems due to inhalation.

Global Concerns: Climate Change
Black carbon from car exhaust

There is no longer any scientific dispute that human production of greenhouse gases, including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), are responsible for the unprecedented rate of warming observed over the past century. In addition to these three greenhouse gases, black carbon, a fraction of PM, is a significant climate forcing pollutant.

Black Carbon

A product of inefficient combustion, black carbon, also known as soot, consists of microscopic solid particles of incompletely burned organic matter. Black carbon is a potent warmer, exerting effects on the global climate both while suspended in the atmosphere and when deposited on snow and ice. The most pernicious characteristic of black carbon from a climatic perspective is its dark color and correspondingly low albedo, or reflectivity. Because of this dark coloring, black carbon absorbs heat from sunlight. A recent study found that soot is warming the climate about twice as fast as scientists had estimated, putting soot second behind the dominant agent forcing warming, carbon dioxide, which accounts for 1.66 W/m2.

Sulfur in Gasoline
Sulfur in Diesel

Modern gasoline engines use computer controlled intake port fuel injection and increasingly direct injection (so called GDI) with feedback control based on an oxygen sensor to meter precisely the quantity and timing of fuel delivered to the engine. Control of in-cylinder mixing and use of high-energy ignition promote nearly complete combustion. The three-way catalyst provides greater than 90% reduction of carbon monoxide, hydrocarbons, and oxides of nitrogen. Designs for rapid warm-up minimize cold-start emissions. On-board diagnostic (OBD) systems sense emissions systems performance and identify component failures. Durability in excess of 160,000 km, with minimal maintenance, is now common.

Sulfur in gasoline reduces the efficiency of catalysts and adversely affects heated exhaust gas oxygen sensors. High sulfur gasoline is a barrier to the introduction of new lean burn technologies using De-NOX catalysts, while low sulfur gasoline will enable new and future conventional vehicle technologies to realize their full benefits. If sulfur levels are lowered, existing vehicles equipped with catalysts will generally have improved emissions.

Based on the experience with advanced gasoline fueled vehicle emissions controls, it is concluded that most gasoline vehicles (other than lean Direct Injection) meeting both Euro 5 and Euro 6 emissions standards should perform satisfactorily with gasoline having a maximum sulfur content of 50 ppm. However this will depend on how much ‘margin’ there is between the actual emissions performance and the limit value, and the higher levels of sulfur may impact on the ability to meet the limit values at full durability of 160 000 km. If and when they shift to 10 ppm maximum sulfur fuels, their performance will improve.

The United States and the state of California have recently adopted even more stringent emissions requirements, the Tier 3 or LEV lll standards. To ensure that the full range of light duty vehicles can comply with these requirements over the regulatory full useful life, ultra low sulfur gasoline (10 ppm sulfur average) is required.

Sulfur in Diesel Fuel
Tons of Directly Emitted PM from Diesel Fuels Sulfur

The contribution of the sulfur content of diesel fuel to exhaust particulate emissions has been well established with a general linear relationship between fuel sulfur levels and the sulfate fraction of particulate emissions. An indirect relationship also exists as some emissions of sulfur dioxide will eventually be converted in the atmosphere to sulfate PM.

For diesel vehicles with no controls, the SO2 and PM emissions is directly related to the amount of sulfur in the fuel. The amount of SO3 emissions is also directly proportional to the amount of sulfur contained in the fuel. In the oxygen-rich exhaust of diesel vehicles several percent of the SO2 formed during combustion is oxidized to SO3, which dissolves in the water vapor present to form sulfuric acid (H2SO4) vapor. H2SO4 forms very small (so called ultrafine) particles in diesel exhaust which are considered especially hazardous because of their ability to penetrate deeply into the lungs. Even though sulfate particles account for only a small fraction of particle volume or mass, they account for a large fraction of particle numbers.

According to the US EPA, approximately 2% of the sulfur in the diesel fuel is converted to direct PM emissions. In addition, SO2 emissions can lead to secondary particle formation—particles that form in the ambient air. US EPA models predict that over 12% of the SO2 emitted in urban areas is converted in the atmosphere to sulfate PM. Urban areas would benefit most from reductions in SO2 emissions, as polluted urban air has higher concentrations of the constituents that catalyze the SO2-to-sulfate reaction. Even with vehicles without advanced pollution controls, reductions of fuel sulfur levels would likely have a significant impact on primary and secondary PM concentrations in urban areas.

The primary reason for introducing lower sulfur vehicle fuels is to enable the introduction of emissions control devices that can significantly reduce vehicle emissions and to allow them achieve their full emissions reduction potential. These technologies are already in place in some countries and are continuously being improved to further control vehicle emissions. However, these technologies generally require specific fuel qualities, often including low sulfur levels

Impact of Sulfur on Diesel Oxidation Catalysts
diesel catalyst

Light duty diesel engines (<3.5 tons gross vehicle weight (GVW)) generally require diesel oxidation catalysts (DOCs) to comply with Euro 2 or more stringent vehicle emission standards. Oxidation catalysts lower HCs, CO and PM, typically removing around 30% of total particle mass emissions through oxidation of a large proportion of the soluble organic fraction. The conversion of sulfur on the catalyst from SO2 to SO3 reduces the availability of active sites on the catalyst surface and therefore reduces catalyst effectiveness. The effectiveness of DOCs is dramatically reduced by sulfur in diesel fuel, and therefore they should be used only in areas which have fuel sulfur levels of 500 ppm or below.

Impact of Sulfur on Diesel Particulate Filters
A Diesel Particulate Filter

Diesel particulate filters (DPFs) reliably demonstrate over 95% efficiency in removing PM from diesel exhaust with near-zero (less than 10 parts per million) sulfur fuel use. DPFs are also capable of reducing the total number of particles emitted to levels similar to or even slightly lower than those of gasoline engines. Filters however need to be cleaned, ideally without human intervention, before reaching capacity in order to maintain vehicle performance and fuel and filter efficiency. For light duty vehicles, Euro 5 and 6 so far all have DPFs. For heavy duty vehicles, EURO VI requires DPFs.

The Continuously Regenerating Diesel Particulate Filter (CR-DPF) and the Catalyzed Diesel Particulate Filter (CDPF) are two examples of PM control with passive regeneration, not requiring human intervention. The CR-DPF and CDPF devices were found to achieve 95% efficiency for control of PM emissions with 3 ppm sulfur fuel. Efficiency dropped to zero with 150 ppm sulfur fuel and PM emissions more than double over the baseline with 350 ppm sulfur fuel. Soot emissions also increase with higher sulfur fuel but even with the 350 ppm sulfur fuel DPFs maintain around 50% efficiency for non-sulfate PM. With 50 ppm sulfur fuel, advanced PM filters can work satisfactorily – more than 75% reduction of PM2.5 and smaller particles - although not as well as with 10 ppm sulfur. The systems recover to original PM control efficiency, over 95% with a shift to use of near-zero sulfur fuels, but recovery takes time due to sulfate storage on the catalyst.

Impact of Sulfur on Selective Catalyst Reduction Technology and NOx Adsorbers
SCR NOX Removal System

Selective Catalyst Reduction (SCR) has emerged as the leading NOx reduction technology. SCR uses a reducing agent, injected into the exhaust gas before the catalyst, to achieve high rates of NOx conversion in the oxygen-rich exhaust. Sulfur does not reduce conversion efficiency in SCR systems as directly as in other advanced control technologies, but emissions are impacted. Fuel sulfur will increase the PM emissions from the downstream oxidation catalyst, and sulfur reactions in urea-based SCR systems can also form ammonium bi-sulfate, a respiratory irritant.

NOx adsorbers are also known as NOx storage catalysts or lean NOx traps. NOx adsorber systems are being used in production aftertreatment systems and have demonstrated 95% efficiency in conversion of NOx to N2. However, SOx takes up active sites that should store NOx and that SOx is more difficult to remove; hence efficiency (for NOx removal) is reduced. There is a need for periodic de-SOx with a resulting fuel penalty of 1.5%. However, long-term durability remains an issue. Also, without significant technological breakthroughs, it is generally recognized that this system can only operate with very low sulfur fuels.

Impact of Sulfur on Engine Durability
Car Engine

Sulfur content is also known to have effects on engine wear and deposits, but appears to vary considerably in importance, depending largely on operating conditions. High sulfur content becomes a problem in diesel engines operating at low temperatures or intermittently. Under these conditions there is more moisture condensation, which combines with sulfur compounds to form acids and results in corrosion and excessive engine wear. Generally, the lower the sulfur levels the less the engines wear.

Diesel fuel has natural lubricity properties from compounds including the heavier hydrocarbons and organo-sulfur. Diesel fuel pumps (especially rotary injection pumps in light duty vehicles), without an external lubrication system, rely on the lubricating properties of the fuel to ensure proper operation. Refining processes to remove sulfur and aromatics from diesel fuel tend to also reduce the components that provide natural lubricity. In addition to excessive pump wear and, in some cases, engine failure, certain modes of deterioration in the injection system could also affect the combustion process, and hence emissions. Additives are available to improve lubricity with very low sulfur fuels and should be used with any fuels with 50 ppm sulfur or less.

In conclusion, most light- and heavy-duty vehicles meeting both Euro 5 and Euro 6 emissions standards can perform satisfactorily with fuels having a maximum sulfur content of 50 ppm. The notable exceptions are gasoline direct injection or diesels which use NOx adsorbers to control NOx emissions. If and when they shift to 10 ppm maximum sulfur fuels, their performance will improve. Alternatively, it will not be feasible to adopt Euro 5 or Euro 6 equivalent standards until the maximum sulfur levels in fuels are limited to 50 ppm or less.

Lessons Learnt

Lesson 1

One of the most important lessons learned in the approximately 50-year history of vehicle pollution control worldwide is that vehicles and fuels must be treated as a system. Improvements in vehicles and fuels must proceed in parallel if significant improvements in vehicle related air pollution are to occur. A program that focuses on vehicle standards or fuel quality alone will be less effective than a program designed to improve both in a coordinated fashion.

Lesson 2

A second important lesson is that a program that focuses on cleaning up vehicles and fuels as a system can be successful. Many countries are following the EU system for cleaning up vehicles and fuels and this system has laid out a clear roadmap which carefully links vehicle emissions standards and the associated technologies with appropriate fuel parameters and specifications needed to optimize emissions performance.

Lesson 3

A third important lesson is that most vehicles new and used available for import into developing nations have some form of pollution control technology and without the lower sulfur fuels to enable the efficient operation of these technologies, the vehicles end up having the technologies not functioning optimally, removing any potential clean air gains that could have been available.

The primary reason for introducing lower sulfur vehicle fuels is to enable the introduction of emissions control devices that can significantly reduce vehicle emissions and to allow them to achieve their full emissions reduction potential.

The Tools

There are many tools compiled in this toolkit which can be used to move towards cleaner fuels and vehicles. This chapter will review a cross section of the tools that have been used in many countries over the years.

A. Mandatory Standards

Mandatory standards are the most direct method for adopting cleaner fuels and cleaner vehicles. In most cases, countries model their requirements on the standards already adopted by either Europe, as transposed into United Nations Economic Commission for Europe (UNECE) Regulations, or the United States. Very often countries will make slight variations to suit local conditions or select a different mix of requirements. For example, with regard to vehicle emissions standards:

  • When Brazil first put in place its PROCONVE program during the mid-1980’s, it took account of the widespread use of alcohol in its gasoline and added an aldehyde standard to what were otherwise similar to the US light duty vehicle requirements.
  • Early this century, Hong Kong realized that the first few generations of European standards provided weaker requirements for diesel cars than for gasoline cars for NOx and PM; since these were the most serious air pollution challenges in the region, Hong Kong adopted European requirements for gasoline cars but California’s much more stringent requirements for diesels.
  • As evaporative emissions become a larger fraction of light duty gasoline vehicle total hydrocarbon emissions, countries such as China are considering adding the US evaporative standards and even the Onboard Refueling Vapor Recovery requirements to their China 6 limits. Beijing will likely introduce these requirements earlier than the national government.

Similarly with regard to fuels, most countries tended to follow the US or European roadmaps for lead and sulfur levels but varied some of the other parameters depending on local conditions. For example:

  • China’s clean fuels roadmap for gasoline varies olefin limits from those in Europe in recognition of the differing refinery configurations in China.
  • Volatility requirements, expressed as Reid Vapor Pressure (RVP) often vary from those adopted by Europe or the US, based on the ambient temperature conditions in a given country or region within the country or season.

Adopting fixed standards for vehicles and fuels and a time schedule for their implementation has the advantage of removing uncertainty for all the stakeholders involved. Vehicle and fuel providers know what will be required of them and can plan and if necessary invest accordingly. Similarly, their customers can anticipate the types of products that will be available to them and when. And environmental and health officials can estimate the future trajectory of vehicle emissions and possible consequences.

In adopting and implementing standards for fuels and new vehicles sufficient resources are needed for a strong and effective compliance program. Details of the fuels and vehicles compliance program in the US are provided under Case Studies.

B. Import Restrictions

Many countries import some or all of their vehicles and those imported vehicles can be either new or used. Placing restrictions on the types and quality of imports can be a very important tool and can take many forms:

New Vehicle Standards

As noted above, such standards are a very effective tool for reducing vehicle emissions.

Used Vehicle Standards

Many countries import large numbers of used vehicles each year and the emissions from these vehicles can have wide variations from relatively clean to highly polluting. For example, many vehicles imported into Mexico from the United States are old and poorly maintained, inexpensive vehicles which are highly polluting. These so called Chocolates are a major concern to Mexico’s environmental authorities. Under consideration is some kind of inspection scheme that could weed out the highest polluting vehicles and prevent them from entering the country. New Zealand has instituted such an approach where all imported cars are given a simple inspection test to assure that at a minimum the catalytic converter is functioning.

Another approach assumes that as a vehicle ages its pollution control technology will generally deteriorate. Therefore some countries will limit imports to vehicles that are less than a certain age – 10 years or 5 years or even 3 years. For example, Kenya has adopted a restriction that prohibits imported vehicles that are over 8 years old.

C. Economic Incentives

Economic incentives such as tax variations or price variations can also play a very important role in shaping the phase in of cleaner vehicles and fuels and these have been used very creatively in the past. Many examples exist including:

Economic Incentives
  • When Hong Kong was experiencing issues associated with the introduction of lead free gasoline, one challenge in particular stood out: many fueling stations were quite small and were unable to have two pumps, one with leaded gasoline and one with unleaded. Since some customers still wanted leaded gas, Hong Kong authorities felt that it would be difficult and even perhaps inappropriate to mandate a complete switch overnight. Their solution was to adopt a tax policy that while allowing both fuels to be sold made clear that unleaded fuel would be less expensive than leaded. Within only a few months of adopting this policy, the vast majority of Hong Kong’s consumers had opted for the unleaded fuel and it rapidly dominated the market. As demand for the more expensive leaded fuel gradually disappeared Hong Kong was able to make lead free mandatory.
  • Thailand faced a similar challenge in that different customers wanted different fuels. Recognizing the routine fluctuations in the price of crude oil in the global marketplace and the impact of this on the price of gasoline. As the price of crude oil rose, they allowed the retail prices of leaded and unleaded gasoline to rise accordingly. However, when the market price of crude oil went down, they only allowed the price of unleaded gasoline to decline, locking in the high price of the leaded fuel. As the gap between leaded and unleaded widened, the market shifted almost entirely to unleaded and demand for leaded fuel almost disappeared. Thai officials were then able to ban leaded gasoline with almost no public backlash.
  • Several European countries adopted creative tax policies to incentivize cleaner vehicles with catalytic converters (and in later years particulate filters) and unleaded and lower sulfur fuels as key elements moving toward mandatory requirements.

D. Use Restrictions

Electric cars charging

Another approach used mainly by cities to incentivize the switch to cleaner vehicles was clean vehicle zones or low emissions zones (LEZs). A wide variety of cities and towns across Europe operate or are preparing LEZs, to help meet the EU health-based air quality limit values, where the most polluting vehicles are regulated. This means that vehicles may be banned or in some cases pay a fee if they enter the LEZ when their emissions are over a set level

Different vehicles are regulated, depending on the local conditions. All LEZs affect heavy duty vehicles, some also affect diesel vans, others also affect diesel and gasoline cars; in Italy, motor cycles and three-wheelers are also included.

One of the most famous LEZs is in London which has several elements and is constantly evolving. In London, if you drive an electric car, you can drive in and out of the city’s central zone without paying the steep $15.50 (£10) daily congestion charge. Since 2008, certain diesel-powered trucks, buses and large vans are “deterred” from driving in the city. The LEZ emissions standards are based on European emission standards relating to particulate matter (PM), which are emitted by vehicles, which have an effect on health. The following vehicles are not charged:

  • Larger vans and minibuses that meet the Euro 3
  • Lorries, buses, and coaches that meet Euro IV.
  • Cars and motorcycles

The Mayor of London has indicated that he is planning to turn the entire downtown core into an “Ultra-Low Emission Zone,” admitting only battery electrics and unspecified “low-emission vehicles” by 2020. This would include more than 1,600 hybrid buses for London by 2016 and all of the city’s new black taxis to be zero emission by 2020.

LEZ Impact:

Another very successful program is in Berlin. The program started in 2008 and at that time, only diesel vehicles that met Euro 2 standards or better were allowed into the center of the city. Euro 1 diesel vehicles could also be admitted but only if they were retrofitted to reduce PM emissions. Gasoline vehicles had to be Euro 1 or cleaner. On January 1, 2010, the program was further tightened with only diesel vehicles meeting Euro 4 or Euro 3 with a particulate filter being allowed.  The illustration 'LEZ impact: change in particle emissions in berlin' indicates that the program has been a great success.

Beijing has a similar program in place which has expanded over time. Initially dirtier (so called yellow label vehicles) were banned from the central part of the city bounded by the second Ring Road over the normal work day (7 AM to 7 PM). Most recently these vehicles are banned from entering the area bounded by the 5th Ring Road

E. Special Exemptions For advanced technologies

There have been many steps taken by countries and cities around the world to stimulate the development and purchase of advanced technology vehicles. For example, as noted under 'Use Restrictions', London provides an exemption from its congestion charge scheme for electric vehicles. A few other examples include:

Exemptions from Episodic Restrictions

When Berlin adopted a high pollution episode scheme several years ago, it provided that only vehicles meeting the more stringent emissions regulations would be allowed to drive in the city when pollution levels exceeded certain hazardous limits. As a result, the city had one of the cleanest car fleets in Germany.

Car Pool Lane Privileges

In the United States, the State of Virginia exempted hybrid electric cars from its car pool lane restrictions. As a result Virginians had a much higher sales fraction of hybrids than other parts of the country.

Sales Restriction Exemptions

Beijing, China has adopted a monthly limit on the number of new vehicles that can be sold and selects eligible purchasers using a lottery system. Purchases of electric vehicles are exempted from the system and can be purchased with no limitation.

F. Voluntary Incentive Programs

SmartWay Graphic

There are several voluntary incentive programs available to entice vehicle owners towards cleaner transportation. One such example is the SmartWay Program.

The SmartWay Program is a public-private initiative between the US EPA, large and small trucking companies, rail carriers, logistics companies, commercial manufacturers, retailers, and other federal and state agencies. Its purpose is to improve fuel efficiency and the environmental performance (reduction of both greenhouse gas emissions and air pollution) of goods movement supply chains.

Launched in 2004, SmartWay is an EPA program that reduces transportation-related emissions by creating incentives to improve freight supply chain energy and environmental efficiency. It aims to accelerate the availability, adoption and market penetration of advanced fuel efficient technologies and operational practices in the freight supply chain, while helping companies save fuel, lower costs and reduce adverse environmental impacts. EPA helps SmartWay Partners move more goods, more miles with lower emissions and less energy.

In its first decade, the program is estimated by EPA to have achieved significant benefits including:

  • SmartWay partners have saved 120.7 million barrels of oil, saving $16.8 billion dollars to date.
  • SmartWay’s clean air achievements are estimated at 51.6 MMT CO2, 738,000 tons NOx, and 37,000 tons PM reduced so far helping protect the health and well-being of citizens, especially in low-income communities near ports, truck stops, and borders.
  • The United Nations, the World Bank, the Commission for Environmental Cooperation, as well as the governments of China, Mexico and Canada, have projects and programs that rely upon SmartWay’s technical assistance, methods and tools.
  • US ports rely on SmartWay’s Port Drayage Truck program to help reduce pollution and address environmental justice concerns in and around major US ports.

Similar efforts are underway in other parts of the world, building on this experience. A good example is the Green Freight China Program organized by Clean Air Asia with support from China Sustainable Energy Program (Energy Foundation) and partners (Ministry of Transport, US EPA and others). Its premise is that City level and regional level projects for the freight sector will be successful and sustained only if an integrated policy package is in place nationally, due to the freight being carried across regional boundaries. A Green Freight China Program is being designed that focuses on energy efficiency and reduced GHG and air pollutants.  

Measures to reduce fuel use and emissions from trucks include:

  • Vehicle activity and driving pattern improvement
  • Enhanced maintenance
  • Tire and wheel technologies and equipment
  • Aerodynamics technologies and equipment
  • Idling control through technologies and behavior
  • Fuel, oil and lubricant improvement
  • Oil by-pass filtration system
  • Emissions control technologies
  • Fleet and engine modernization

G. Vehicle Scrappage Programs

vehicle scrappage

Several mandatory and voluntary vehicle scrappage programs exist in many countries and most of them are government and industry funded.  Vehicle scrappage programs promote the acceleration for replacement of old vehicles with newer ones. The older high polluting vehicles are taken off the road and destroyed.  Vehicle owners can receive different incentives offered by the local programs which can include monetary reductions when purchasing new vehicle or incentives towards public transportation or cleaner mode of transportation.  Pollution levels can be greatly reduced.

China is attempting to bring this about and has mandated that all yellow label vehicles across the country be destroyed by the end of 2017; in the three main regions, all these vehicles are to be scrapped by the end of 2015. All gasoline vehicles that were produced without a catalyst (so called Pre-Euro or pre 2000 Model Year) and all pre Euro 3 diesel vehicles receive a yellow registration label.

H. Court Actions


In some countries, citizens have gone to court to challenge governments to do more to provide them with clean, healthy air and this can be the basis for accelerating the move to clean fuels and vehicles. Examples include:

Experience in Europe: The binding character of the limit values also emerges from the individual right of every EU citizen living in a non-attainment area, that the air quality (AQ) management authority undertakes all proportionate efforts to bring air pollution below the limit value or at least to reduce the excess of the limit value to the extent possible. That an individual right for action emerges from the excess of the AQ limit values was confirmed by the European Court of Justice, ruling on request of the German Superior Administrative Court, which in turn confirmed the claim of a citizen living along a heavily polluted arterial road in Munich, that the administration had not brought forward appropriate measures to reduce air pollution in the neighborhood and that more ambitious measures needed to be implemented to minimize the excess of the limit values and to meet them as soon as possible. As a result, the city of Munich had to revise its AQ plan by adding new measures. Forced by the court ruling, Munich eventually introduced a low emission zone where vehicles not meeting certain emission standards were banned. Only recently, the European Court of Justice clarified, again on request of the German Superior Court, that NGOs also have the right to file an action against insufficient local air quality planning. 

Experience in India: Fuel specifications based on environmental consideration were for the first time notified in the country by the Ministry of Environment & Forests in April 1996 for achievement by 2000. These norms mandating lead free gasoline were incorporated in the Bureau of Indian Standards (BIS) 2000 standards. Further, based on the Supreme Court order of April 1999, Ministry of Surface Transport (MoST) notified Bharat Stage-I (BIS 2000) and Bharat Stage-II vehicle emission norms broadly equivalent to Euro I and Euro II for introduction in entire India and NCR respectively.

In further response to the Supreme Court, the Ministry of Petroleum & Natural Gas (MoP&NG), Government of India constituted an Expert Committee, under the Chairmanship of the  then Director General, Council of Scientific & Industrial Research (CSIR) in 2001 to recommend an Auto Fuel Policy for the country including major cities; to devise a road map for its implementation; to recommend suitable auto fuels and their specifications considering the availability and logistics of fuel supplies, the processing economics of automotive fuels, and the possibilities of multi-fuel use in different categories of vehicles; to recommend attributes of automobile technologies, fiscal measures for ensuring minimization of social cost of meeting a given level of environmental quality and institutional mechanisms for certification of vehicles and fuels, as also the monitoring and enforcement measures.  The Expert Committee submitted their report to the Government of India in August 2002, which included their recommendations for achieving the desired objectives. Based on these recommendations, MoP&NG released the “Auto Fuel Policy” as approved by the Government in October 2003, which contained the recommendations for implementation, along-with the time frame, wherever applicable.

The Auto Fuel Policy (2003) addressed measures to cover various areas in which action was required viz. vehicular emission norms, fuel quality and the standard of CNG/LPG kits, measures to reduce emissions from in-use vehicles, vehicle technology, air quality data and Research & Development. It also covered air quality data and health effects of air pollution.

I. Inspection and Maintenance (I/M)

Purpose of Inspection and Maintenance

Vehicles that are properly tuned and maintained tend to be cleaner than vehicles that are not. Modern vehicles equipped with advanced pollution controls are even more dependent on properly functioning components to keep pollution levels low. Minor malfunctions in the air/fuel or spark management systems can increase emissions significantly.  Major malfunctions can cause emissions to increase dramatically.  A relatively small number of vehicles with serious malfunctions frequently cause the majority of the vehicle-related pollution problem. Unfortunately, it is rarely obvious which vehicles fall into this category, as the emissions themselves may not be noticeable and emission control malfunctions do not necessarily affect vehicle driveability. Effective vehicle inspection programs based on periodically subjecting vehicles to a short test can identify these problem cars and, by requiring a retest after necessary maintenance assures their repair. The combination of inspection (I) and remedial maintenance (M) has become known as I/M.

Emmision Reduction Following Repair of Failed Vehicles

It has been well established that properly designed and operated I/M programs are capable of significantly reducing emissions. For example in one evaluation of the long term benefits of the British Columbia I/M program, it was determined that over the first 8 years of the program, HC emissions were reduced by 34.3%, CO by 38.4% and NOx by 10.3%. In addition to the emissions reductions, the audit program found that fuel economy for the failed vehicles improved by approximately 5.5% following repairs.

  • Targeted I/M programs can contribute substantially to reduce the pollution caused by such vehicles. But there are also many challenges involved with implementing an effective I/M program and policymakers should make a decision to launch (or strengthen) an I/M program only if fully cognizant of the challenges involved.  Some of these challenges are described in a report by the US Agency for International Development. If a country decides to introduce I/M programs, certain overriding principles should be followed to help ensure successful programs:
  • As vehicle technology advances, more sophisticated test procedures are necessary including loaded mode tests that use a dynamometer to simulate the work which an engine must perform in actual driving.
  • Tightening of new vehicle emission standards should be followed by a concomitant tightening of in-use standards for those newer model vehicles. Policymakers must assure that appropriate in use standards are set for vehicles, which account for the technology advances which result from tighter new vehicle standards.
  • In addition, policymakers must assure that the in use standards applied in the I/M programs appropriately reflect the differences between each group. In addition, policymakers must assess whether the I/M test procedures may also need to be different for vehicles with different pollution control technologies.
  • Further, the pollutants of concern will differ between diesel-fuelled vehicles (PM, smoke and NOx) and gasoline (petrol) fuelled vehicles (CO, HC and NOx). Policymakers should account for these differences in designing their I/M programs.
  • When an I/M program is initiated, if standards are set too stringently, most vehicles could fail placing a great strain on the service sector as well as being politically unacceptable. Policymakers should adopt initial standards that only fail the worst 15% to 20% of the vehicle fleet and then gradually tighten the standards as the service industry and maintenance practices improve.
Structure of the Program

The first decision that is usually made regarding an I/M system is the fundamental structure of the program and this is often the key determinant of the overall success or failure of the effort.  Several key principles should guide policymakers in deciding on the I/M program structure:

Inspection and Maintenance
  • Experience indicates that centralized I/M systems (sometimes called test only systems) where the inspection function is separated from the maintenance function have produced the best result. Decentralized systems where inspections and repairs are combined are very difficult to supervise and audit and have been found to be subject to corruption and poor quality control. Policymakers should be especially cognizant of the international experience in this regard and resist the adoption of programs that combine testing with repair and that are very unlikely to achieve significant emissions reductions.
  • In defining the structure of the I/M system, policymakers should assure that there is a careful and thorough dialogue among all relevant stakeholders. These include providers, regulators, enforcers/police, vehicle manufacturers, the driving public and the media.
  • Experience from across the world has demonstrated that while governments should regulate I/M programs the actual implementation of I/M programs can best be carried out by the private sector. Policymakers should assure that a carefully designed and well thought out bidding document is prepared in an open and transparent manner and that all potential bidders are given a fair opportunity to compete for the final contract.
  • Governments contemplating the establishment of an I/M system or expanding the scope of an I/M system need to consider:
    1. Whether they have adopted the appropriate in use vehicle emissions standards and test procedures on which to base I/M.
    2. If there is the institutional capacity and willingness to enforce an I/M program.
    3. Whether the repair sector has been trained sufficiently to be able to carry out the repairs on cars which fail the tests.
    If any of these aspects are found to be deficient, policymakers should take all appropriate steps to rectify the situation.
  • With regard to the repair sector, the vehicle manufacturers can play an important role in providing training and policymakers should take steps to involve them in the development of an overall strategy to upgrade the repair industry.
Institutional – Administrative Set up

The single most important determining factor for success of I/M is support by senior decision makers and the institutional capacity to manage and regulate the system. Where such institutional capacity is insufficient a weak regulatory framework results. Inadequate funding and enforcement could lead to a system that is plagued by corruption and poor quality control. Policymakers should adhere to the following principles, therefore, in setting up the I/M system:

  • Policymakers must assure that an adequate fee structure is developed in which the affected vehicle owners pay the full costs of the I/M program including the costs of auditing and overseeing the program by government or private auditors. This follows the principle of the polluter pays.
  • Within countries that have a combined roadworthiness and emission-testing program, the responsibility is often shared between the Departments of Transport and Environment. Poor coordination between these two departments can hamper efforts to strengthen I/M. Policymakers should assure that there is a full dialogue with all appropriate ministries or departments at the early stages of program design and that full agreement is worked out regarding specific roles and responsibilities.
  • In those countries where responsibility is shared between national and local government organizations coordination problems can also occur in the implementation of existing I/M programs as well as in the strengthening of the I/M system.  Again policymakers should assure that there is a full dialogue with all appropriate ministries or departments at the early stages of program design and that full agreement is worked out regarding specific roles and responsibilities.
  • Any I/M system needs to account for new vehicle emissions standards, which in most cases are issued by national governments. Policymakers should strive to develop I/M systems within a national framework.
  • Overall success in an I/M program depends in part on assuring that all vehicles that are intended to participate in the program are actually inspected and repaired if necessary. Experience has demonstrated that the most effective I/M programs are those that are linked to registration of vehicles, i.e., failure to present proof of passing an inspection leads to denial of registration. Policymakers should therefore carefully develop and implement a registration based enforcement system for all affected vehicles.
  • A well-functioning I/M system will include a data management system that ensures that all test data are transmitted on a regular basis to a central database. This will be easier if I/M stations are linked by computers that automatically transmit information on a real time basis. This is much easier in a centralized system with a limited number of contractors than in the case of a decentralized system with a large number of independent workshops. In designing the program, policymakers should assure that a good data management system is included and assure that sufficient funds are included in the fee structure to manage and operate the system.
  • Policymakers should also be aware that increased reliance on data management centres will make it necessary to strengthen the quality of the overall database on vehicles in actual use.
Technical Issues

Many I/M systems, often those operated by the government, lack the commitment of resources or the requirement to assure that hardware is maintained and upgraded as appropriate. Also funds for calibration of equipment are often inadequate. Often, limited attention is paid to assure adequate training of staff that carries out the inspections.

  • One remedy noted earlier which policymakers should carefully consider is privatising such programs and adopting a fee structure which provides adequate funds.
  • The shift towards more stringent emission standards for new vehicles should be followed by tighter in-use standards for the newer models. The test procedure should be shifted to a “loaded test” rather than “idle test” when new vehicle standards result in the introduction of catalyst technology on vehicles. This will require new, additional test equipment including chassis dynamometers. The costs of such equipment will make it difficult for small-scale workshops to take part in the implementation of an I/M program, which is another reason for considering a centralized system.
  • Since most developing countries have adopted EU standards for new vehicles, it may be more appropriate to adopt a European short test rather than the US derived IM240. An example of such a test is shown in the image below.
  • A potentially serious problem, especially where most vehicles still are equipped with simple carburettor technology, is the “Clean for a Day” syndrome, in which vehicles are tuned to pass the test and then immediately readjusted to a high pollution condition afterwards. To deal with this problem, policymakers must give attention to complementary in use test programs such as roadside screening or remote sensing (the above image shows a typical remote sensing set-up.).
  • There are certain countries or cities which are leading the way with respect to testing of certain types of vehicles such as the Smoky Vehicle Control Program in Hong Kong which involves dynamometer smoke testing for light and heavy duty diesel vehicles. Policymakers should consult with the technical leaders in the region as they develop their programs.
  • Emphasis in I/M should be on identification of gross polluters within each technology category. Remote sensing (RSD) is evolving and may play an important role in identifying the gross polluting vehicles, especially where most vehicles are low tech. It might be less suitable for more advanced technologies unless further improvements are made. Currently, most experience with RSD has been with clean screening as a means to reduce the testing load although dirty screening programs are also in effect or being developed.
  • In designing programs, policymakers should assure that frequency of inspections varies for vehicles with differing mileage accumulation rates and with more or less durable emission control systems. For example, taxicabs typically accumulate far more mileage in a given period than do private cars and therefore they should be subject to more frequent inspections.
Public Awareness
Public Awareness

Public perceptions regarding the effectiveness and transparency of I/M systems will heavily influence the willingness of the general public to cooperate with I/M regimes imposed by the government. To ensure a positive public perception it is important that the public understand the public health need for the program and believe that it is fair and effective. The US EPA has developed a toolkit for public participation.

Experience indicates that the driving public is on average more interested in roadworthiness and safety of vehicles than in emission levels because the linkage between vehicle roadworthiness and the safety of drivers, passengers and pedestrians is more apparent. To ensure the required public acceptance of I/M programs and their willing participation in maintenance and inspection of vehicles I/M programs will have to considerably strengthen the public awareness-raising component of their programs. Particular emphasis should be placed on the health benefits that can result from a successful program.

Environmental NGOs lack resources and often have limited understanding of vehicle emission standards and I/M issues. This limits the effectiveness of these groups in encouraging government officials to assure that good quality I/M programs are put in place.

  • Considering the above, policymakers should develop a strong and ongoing public awareness component to the program that routinely informs the public regarding the need for the program, the benefits which it is having and the overall performance. A special focus of the public awareness campaign should be on environmental NGOs who need to have their understanding and capacity upgraded. Again, policymakers must assure that sufficient funds for this effort are included in the inspection fee structure.
  • Policymakers must develop performance standards for I/M stations that will guarantee fast and reliable testing for the public; poorly performing stations must be penalized as well. Performance measures could include typical waiting times as well as pass/fail rates.
  • Policymakers also need to think about methods to be employed to get a better cooperation from the public in I/M programs. Consideration should be given to tax incentives, lower registration fees for cleaner vehicles, or linkage to vehicle insurance rates.
Quality Assurance – Audit

I/M programs have often been associated with fraud and corruption. Failure to address these issues will seriously compromise the credibility of effectiveness of I/M systems.


Governments often experience difficulties in setting up effective quality assurance and audit mechanisms of the I/M systems in their countries. Yet, a well-functioning audit and quality assurance system is crucial for the acceptance and success of any I/M system. Audits can be implemented by a special unit in the responsible government department or can be outsourced to a private sector firm provided it is not operating a part of the I/M system. These private sector providers should also not provide training or consultancy services to the I/M provider.

  • Policymakers should assure that such auditing functions are fully built into the overall program design and accounted for in the fee structure. Further, in designing such auditing systems, as a general rule, it can be stated that the less reliance there is on human judgment or manual actions, the more reliable the result.
  • Policymakers should also assure that test fees are set at a reasonable level that will allow private sector operators to make a sufficient profit to maintain, replace and upgrade equipment as required.
  • The duties of the regulatory agency are often not well defined and the agency is usually not well staffed. Policymakers should define the duties of the regulatory agency to include design of the I/M system, setting appropriate test procedures and standards, assuring proper operation of the I/M program and careful auditing. Where audits identify problems, policymakers should insure that the regulatory agency is authorized to and has the capacity to enforce the requirements, including the removal of the license to carry out the inspection by offending operators.
  • A key element of a successful I/M program that is frequently neglected in the program design is how to enforce the case against corrupt entities, especially inspectors. Policymakers must give careful attention and thought to what are appropriate sanctions so as to assure that a workable system is in place.
Roadside testing programs
Roadside Testing

Roadside testing can complement a more comprehensive Motor Vehicle Inspection System but not replace it. Policymakers should insure that roadside testing is designed as a complement to but not an alternative to testing in fixed stations. The roadside testing should primarily have the function of identification of gross polluting vehicles.

  • Apart from the privatisation of the inspection centres, policymakers should also consider whether to outsource roadside apprehension to the private sector. They should insure that the inspection fee fully provides for the costs of an adequate roadside apprehension program.
  • Certain countries have tried to strengthen enforcement by allowing enforcers to retain a part of the fines collected from apprehended vehicles. The effectiveness of this approach needs to be studied by policymakers to be sure that this doesn’t increase the likelihood of corrupting the overall system.
Maintenance: The “M” in I/M

While a great deal of attention is being paid to the I in I/M, it is the M that actually reduces emissions. Very often, the quality of repairs is weak and needs special attention. Therefore, in designing I/M programs policymakers need to include a particular focus on this issue. This is especially true in countries or regions where the service sector is very informal and lacks good training or equipment.

Engine Inspection
  • The service industry should have sufficient equipment to properly repair vehicles. In addition, adequate training must be made available so that the mechanics and technicians are sufficiently skilled to repair the failed vehicles that come to their shops.
  • In tightening the I/M requirements, policymakers should pay careful attention to assuring that the service industry has sufficient lead-time to equip itself to repair failing vehicles. A one year transition from the time testing is initiated until mandatory repairs are required is a reasonable phase in.
  • Policymakers should also insure that good lines of communication exist between the repair industry and the I/M managers so that problem vehicles can be resolved. Routine meetings should be arranged to discuss problems.
  • One mechanism for resolving disputes or difficulties with individual vehicles is the introduction of referee stations, where owners can get a second opinion and advice about appropriate repairs. Policymakers should carefully consider provision of one or more referee stations in the overall design of the program.
  • Policy makers should also address quality assurance for spare parts. One approach that should be considered is requiring parts suppliers to warranty the performance of their parts and to label the details of the warranty on the packaging.

How to Implement a Clean Fuels and Vehicles Program

As countries or regions or cities consider a move to cleaner fuels and vehicles, they find themselves in many different circumstances - a strong or weak government agency with the power to mandate requirements, a domestic industry that produces vehicles and or fuels and that is an important source of jobs versus one that only imports these products or some hybrid of these, for example. But whatever the structural situation might be, a usual starting point involves raising public awareness of the health or environmental consequences of inaction.

A.    Educate the Public and get their support

public education

Without strong public support it is highly unlikely that it will be possible to move forward with a strong and effective clean vehicles and fuels program. First it will be important to pull together a good summary of available information. International information is easily available and is briefly summarized later in this website. Health information highlighting potential adverse impacts on children, the elderly and other sensitive groups is usually most important. Beyond health impacts, in some areas, other environmental effects may be considered very important by some influential groups. (In Europe, for example, dying forests and lakes due to acidification motivated action as much as health concerns.)

Where local data is available to supplement international data that should be gathered as well. This can be critically important.

Getting this information to the public and policy makers and policy shakers is then critical. Press events, press background briefings, public workshops and other activities of this type can be useful means to get the word out. Often, the NGO community can play a critical role in doing this.

The affected industries – at a minimum the oil industry and the vehicle industry – need to be involved in this process. At best, they will support what you are trying to do. But even if not, it is wise to know their concerns and to learn what their objections or disagreements might be.

At the end of the day, unless there is a perceived need for action by a cross section of the public, it will likely not occur.

B.    Identify The Decision-makers that Must Be Convinced to Act

This can vary widely from country to country

    public education
  • In the US, the EPA has the power to set vehicle and fuel standards but often there will not be one agency or organization blessed with this power.
  • In Europe, there are different roles with the Commission in the lead initially to develop proposals but with the Member States and the Parliament playing critical roles and having the power to strengthen or weaken whatever the Commission proposed before it is finalized.
  • In India, special expert committees have played a key role with the courts often applying important pressure.
  • In China, multiple organizations are involved – certainly the Ministry of Environment Protection (MEP) but also the State Council and others. Beyond the national government, local efforts such as those in Beijing and Shanghai can play a critical leadership role.

Each country is unique with its own political culture and power structure. This must be understood in order to be effective in bringing about real action.

C.    Find a Champion or Champions

Within the decision making structure or power structure, it is usually important to find a person or an organization that supports your objectives for clean vehicles and fuels and to do what you can to help that person.

Find a champion

D.    Gather the Facts

At the end of the day, policy makers will want to know and will need to know the facts:

  • Why are clean vehicles and fuels needed?
  • Is this possible technically? Politically? Economically?
  • How much will it cost?
  • Who will be affected?
  • How much time is needed

E.    Match Tools to Circumstance

Is a mandatory regulation the most likely initial step to bring about success or will tax incentives or disincentives work better in your country or region? Important considerations might include:

  • Are all vehicles imported or are some vehicles manufactured or assembled in your country?
  • Is there a local refinery industry or is all your gasoline and diesel imported?
  • If vehicles or fuels are imported, what is the status of controls in the country or countries from which you import?
  • What are the potential jobs impacts in your country if you move forward toward cleaner vehicles and fuels?

F.    Develop a Strategy to Get Decision - makers to Act

It can be very helpful to determine who will be your allies and who will be you adversaries in this effort and what you need to do to bring them around to your point of view – to make it possible for the outcome to be positive after appropriate debate.

Action Plan

G.    Enforcement

Experience has shown that regulations and standards have limited value unless they are enforced. The following section discusses the details of the enforcement and compliance programs for fuels and vehicles in the United States.

A fuel compliance program is important to ensure that fuels sold at the retail stations meet all the mandated specifications. A fuel compliance program becomes more critical with the use of advanced emission control devices that can be damaged by impurities in fuel (e.g., high sulfur fuel). Identification of compliance points within the fuels distribution system (e.g. port of import, refinery gate) can ease enforcement.

New vehicle emission standards can only serve to protect air quality if vehicular emissions are actually reduced when the vehicles are in normal use. To fully deliver the promise of environmental and health benefits from new vehicle standards, an effective vehicle compliance and enforcement program has to be in place to ensure emissions of new and in-use vehicles are effectively controlled.

USEPA program for light-duty vehicles

H.    Governance

Regulatory Governance

Regulatory governance connects the essential pillars of environmental change which include: impact awareness of the environmental issue, actions to address the environmental issue and the instruments to enable the action to address the environmental issue. Regulatory governance is generally enabled by a central government-led agency that writes the laws and regulations, administers and enforces the regulatory requirements.

For any program including regulatory there needs to be appropriate resources, financial and human to develop, implement and monitor the program. The range in complexity of a program can be correlated to the complexity of the industry and of the flexibilities provided within a program.

Each country or jurisdiction will have different ways of gathering resources to support an initiative such as a regulation. The lead agency will need to submit to the appropriate authorities the requirements for the new initiative. In this case the initiative would be the introduction of clean fuels to the market. Budgets will be needed for each phase of the regulatory process which includes regulatory development, implementation and administration. Once the regulations are implemented there would be the on-going regulatory administration, compliance promotion and enforcement. These units may be separate, but in all cases they should work closely together as illustrated below.

working together
Key Lessons

Some lessons learned on regulatory governance and the development of regulations:

  • Consulting with industry and other government departments is key to the design of a successful regulation.
  • Alignment with major trading partners enables a “level playing field” and smooth trade activity in regards to competition and market forces.
  • The more complex a regulation or instrument, the tougher it is to enforce.
  • But complex regulations/instruments can allow for industry flexibility.
  • Extensive training of administration/enforcement officers and the stakeholder/regulated community helps ensure compliance and a smooth application.
  • Designing the regulation/instrument is the “tip of the iceberg” – much more follows. Implementation and administration can include:
    • Compliance promotion
    • Training
    • Data collection,
    • Reporting
    • Performance measurement
    • Compliance verification
    • Enforcement
    • Amendments, etc.

Case Studies

Canada's Progress in Addressing Clean Fuels and Vehicles

Canada's Progress in Addressing Clean Fuels and Vehicles

Map of Canada

The Canadian Environmental Protection Act (CEPA) gives Environment Canada (EC) broad authority to regulate both vehicles and fuels and EC has used this authority to put a very strong program in place. The CEPA is similar to the US Clean Air Act.  The Canadian vehicle industry is closely integrated with the US industry and many vehicles are manufactured in Canada for the US market. Because of this close integration, the Canadian vehicle industry is strongly supportive of vehicle and fuels regulations that are closely harmonized with the US and that, in fact, has generally occurred. In addition to close consultations with stakeholders in the development of environmental regulations, Environment Canada coordinates closely with its main trading partner, the US.

Environment Canada was created in 1971. Since then the Canadian federal government has adopted increasingly stringent standards for smog-forming emissions from motor vehicles. Several key initiatives helped to develop the Canadian regulatory fuels and vehicles program. There have been considerable efforts by the federal government and industry directed towards providing cleaner gasoline and diesel fuels for Canadians. Fuel related initiatives include the removal of lead in gasoline, the reductions of summer vapor pressure, and lowering benzene in gasoline and lowering sulfur levels in both gasoline and diesel fuels. Many of the federal initiatives were developed on the recommendations from a special committee called the Canadian Council of Ministers of the Environment (CCME) Task Force on Cleaner Vehicles and Fuels (October 1995) with representation from both federal and provincial governments.  Part of the process of the CCME was to determine an appropriate level of sulfur in gasoline and diesel.

On February 19, 2001, the Minister of the Environment announced that the Government would make significant investments in new measures to accelerate action on clean air and published the Federal Agenda on Cleaner Vehicles, Engines and Fuels. The Agenda set out a series of regulatory and non-regulatory measures to be developed and implemented over the next decade to further protect the health of Canadians and the environment by reducing emissions from vehicles, engines and fuels.

The federal Sulphur in Gasoline Regulations took effect July 2002 and required an average gasoline sulfur concentration of 150 mg/kg as of July 2002 and 30 mg/kg as of January 2005.

More recently, Canada has proposed a further tightening of sulfur levels in gasoline. The proposed Regulations Amending the Sulfur in Gasoline Regulations (the proposed SiGR Amendments) would introduce lower limits on the sulfur content of gasoline (down to 10 ppm) in alignment with the United States Environmental Protection Agency (U.S. EPA) Tier 3 fuel standards. The proposed SiGR Amendments are published with the proposed Regulations Amending the On-Road Vehicle and Engine Emission Regulations and Other Regulations Made Under the Canadian Environmental Protection Act, 1999 (the proposed ORVEER Amendments). The proposed ORVEER Amendments would introduce stricter limits on air pollutant emissions from new passenger cars, light-duty trucks and certain heavy-duty vehicles beginning with the 2017 model year in alignment with the United States Environmental Protection Agency (U.S. EPA) Tier 3 vehicle standards. These two regulatory initiatives would work in concert to reduce vehicle air pollutant emissions.

The Sulphur in Diesel Fuel Regulations set maximum limits for sulfur in diesel fuel for use on-road, off-road, in rail (locomotive), vessels, and stationary engines. The goal of the Sulphur in Diesel Fuel Regulations is to ensure that the level of sulphur in diesel fuel used in Canada will not impede the effective operation of advanced emission control technologies installed on vehicles and engines.  

The current and upcoming maximum sulphur limits and effective dates for production, import and sales of diesel fuel in Canada are summarized in
The Regulatory Process

The Sulphur in Diesel Fuel Regulations can be used here to illustrate how a regulation is developed, designed, implemented and then enforced in Canada. The full development of these regulations took place incrementally over 20 years. Specific parts of the diesel pool were addressed in tandem with the vehicles and engines that use that part of the pool. The table shows that on-road diesel was address first and then followed by other parts of the pool.

The first step was to develop the policy for how to address sulfur in diesel fuel. In the mid 1990s, the Canadian government set up a multi-stakeholder process, called the Task Force on Cleaner Vehicles and Fuels, which brought together provincial/territorial governments, vehicle and engine manufacturers, fuel producers and importers, fuel users, and environment and health non-governmental organizations. This inclusive process identified issues and advised the Federal government on priorities for action. The inclusion of all relevant stakeholders ensured broad acceptance of the final recommendations of the Task Force. It also insured that all relevant information was gathered and analyzed. By participating on this task force, staff in the Federal government (engineers, economists, lawyers, health and environmental scientists) gained valuable expertize on fuel related matters, and were able to make internal recommendations to the Minister of the Environment and other relevant members of the Cabinet.

In regards to sulfur in diesel fuel, the Federal government accepted the Task Force recommendation that the level in sulfur in diesel fuel should be lowered through regulation by the Federal government. Prior to this, voluntary and regional approaches had been used. This led to a number of issues: specifically, fuel producers that were voluntarily meeting a lower sulfur level were being undercut in the market by those who were not participating in the voluntary program, and fuel producers preferentially sent batches of low-sulfur diesel to provinces with regulations and sent other (high-sulfur) batches to provinces without regulations which became a “dumping ground” for poor-quality diesel fuel.

Once the policy was approved by Cabinet, regulations were developed. These regulations were legally authorized by the Canadian Environmental Protection Act. The first step was to design how the regulations would work. This was done primarily by engineers with the assistance of lawyers. On vehicle and fuel issues, Canada generally aligns with regulatory actions in the U.S., however it often takes a simpler approach to achieve the same regulatory levels (e.g., through fewer regulatory flexibilities and exemptions). At the same time and building upon the analysis of the task force, the costs and benefits of the regulation were determined (primarily by economists with the assistance of engineers and scientists). Stakeholders, especially fuel producers and importers, were consulted upon the details of the regulatory text and on the costs and benefits of the regulations. This process took several years, but ended in a regulation that met the policy requirements to reduce sulfur in diesel fuel and yet was understood and achievable by the affected fuel producers.

Sufficient time was given before the regulations came into force to allow for the design, construction approval, purchasing, installing and testing of the necessary equipment at the refineries (i.e., about 3 to 4 years). This delay may not be needed if a country only imports diesel fuel and there are already numerous sources of low-sulfur diesel fuel available for the source of imports. Once the regulations were in force, it was essential to the environment, to the engines and to the fuel industry itself that the regulated requirements were complied with. Parties seeking financial advantage by supplying non-complying, less-expensive, high-sulfur diesel fuel have to be identified and prosecuted to ensure environmental goals are met, the engines are not damaged and other fuel suppliers are not undercut in the market.

The first step was to ensure that the regulatees (the fuel producers and importers) understand the regulations and their obligations. Various types of guidance documents were developed, including a very detailed and technical question and answer document, and all inquiries from regulatees were responded to (primarily by the engineers that designed the regulations). In addition, the regulation required fuel producers and importers to provide information on the sulfur level in their diesel fuel on a quarterly and then later an annual basis. Government staff (engineers and administrative staff who administered the regulations) examined this data and compared it to other information to identify if there were issues and flag any such issues to those responsible for enforcing the regulations. This data also forms the basis for annual reports to the public on the level of sulfur in diesel fuel. Fuel producers, vehicle manufactures, fuel users, environment and health groups and provincial governments all find this data to be of considerable use.

It was also necessary to train the enforcement officers who would be enforcing the regulations to ensure that they understood the requirements of the regulations, and how to verify compliance with them. To this end, relevant guidance and training material was developed by the engineers that designed the regulations, and an internal working group of staff from policy, compliance promotion, regions and enforcement was set up and it continues to ensure that any developing issues regarding the regulations are identified and addressed.

After the regulations regarding sulfur in on-road diesel fuel were underway, the regulatory process started again for reducing sulfur in off-road diesel, and then again for the other diesel pools. This incremental approach allowed time for the on-road technology to be adapted for use in the off-road and other pools, and for the spreading out of the costs of sulfur reduction.

The regulations limiting sulphur and lead enabled the introduction of cleaner vehicle and engine regulations.

China's Progress in Addressing Cleaner Fuels and Vehicles

China’s Progress in Addressing Cleaner Fuels and Vehicles


Map of China

The vehicle population in China has experienced significant growth over the past thirty years.  The tremendous growth in the last decade has led China to become the largest vehicle producer and consumer in the world.  Annual sales of on-road vehicles (excluding 2-wheelers and rural vehicles) have grown from roughly 250,000 in 1980 to nearly 22 million vehicles in 2013. Over that same time period, 2-wheeler (motorcycles and electric bikes) annual sales have grown from about 600,000 to a staggering 50+ million. Since 2000, the total stock of cars, trucks, and buses has more than quadrupled from 13.5 to over 60 million vehicles. Over this ten-year span, the total stock of motorcycles has roughly tripled from 68 to over 200 million.

Given the sheer magnitude of vehicle growth over the past decade, the task of curbing the negative impacts of vehicle emissions has taken on increased significance. Looking at the history of efforts to improve air quality, emission control legislation in China has evolved greatly since its inception in the early 1980s. The Figure highlights a few select milestones in China’s mobile source emission control including the establishment and revisions of the Air Pollution Prevention and Control Law, the cornerstone of the air quality program.  The first significant policies targeting vehicle emissions were phased in with the implementation of ‘China I’ standards in Beijing and Shanghai in 1999.

Selected milestones in China’s Vehicle Emission Control Program
Selected milestones in China’s Vehicle Emission Control Program

Despite the massive growth in vehicle stock and activity, China’s vehicle emission control program has been effective in curbing criteria pollutant emissions. During the period from 2000 to 2010, China quickly moved from Euro 1 standards to Euro 4 for light duty vehicles. However, fuel quality did not keep pace because the Ministry of Environmental Protection (MEP) does not have the legal authority to regulate fuel quality. As a result, in 2010, China delayed the introduction of China 4 truck standards until 2012. In 2012, again because of poor fuel quality, the standards for trucks were delayed until July 2013. Even then, press reports indicate that many trucks are still entering the marketplace which do not meet China 4 standards.

One result is that the air pollution problem in many parts of China has reached crisis levels. Just three of 74 major cities recorded met national air quality standards throughout last year according to Wu Xiaoqing, deputy minister for environmental protection. Only Haikou in Hainan, Lhasa in Tibet and Zhoushan in Zhejiang met the new air quality standards.  Wu said the smog-plagued Beijing-Tianjin-Hebei area experienced air pollution on more than 60 per cent of days last year, the worst in the country. Annual average levels of PM2.5 - tiny pollutant particles smaller than 2.5 microns that can penetrate deep into the lungs - reached 106 micrograms per cubic meter in the region, more than 10 times the World Health Organization’s safety limit of 10. The area also has seven of China's 10 most polluted cities. Other built-up regions - city clusters in the Yangtze and Pearl River deltas - also registered chronic smog problems.

China plans to take more than five million ageing yellow label vehicles off the roads this year in a bid to improve air quality, with 330,000 cars set to be decommissioned in Beijing alone, the government said in a new policy document. The State Council said that as many as 5.33 million "yellow label" vehicles that fail to meet Chinese fuel standards will be "eliminated" this year, the document said. As well as the 330,000 cars in Beijing, 660,000 will be withdrawn from the surrounding province of Hebei, home to seven of China's smoggiest cities in 2013.

Beijing plans to limit the total number of cars on the road to 5.6 million this year, with the number allowed to rise to 6 million by 2017. Last year it cut the number of new license plates by 37 percent to 150,000 a year and also paid for another 200,000 ageing vehicles to be upgraded.

The State Council document did not say how the plan would be implemented, but Beijing's municipal government has previously offered subsidies of between 2,500-14,500 Yuan ($400-2,300) to drivers who voluntarily hand in their ageing vehicles to be scrapped.

Beijing currently forbids vehicles that do not meet required standards from entering the city, but officials have admitted that China currently lacks the monitoring and policing capability to ensure all cars make the grade, and drivers have also found ways to avoid detection.

The current emissions standards roadmap for China is summarized below. China 4 standards are currently in effect for cars, trucks and buses. China 5 standards are scheduled to go into effect in 2018 for light duty vehicles; no schedule for China 5 introduction for trucks has yet been announced. The national government has just announced its plan to develop China 6 regulations for all categories of vehicles in 2015 but has not yet indicated its plans for implementation timing.

Current Vehicle Emissions Standards in China

Beijing Makes Strong Case for Aggressive Local Air Pollution Action Plan

Smog in Beijing

Beijing's 5.35 million vehicles consume about 7 million metric tons of fuel and emit about 900,000 metric tons of pollutants annually. Vehicles contribute about 86 percent of carbon monoxide, 57 percent of nitrogen oxides, 38 percent of hydrocarbon, and 22 percent of small particulate matter (PM-2.5) emissions in the city.

As part of an action plan to reduce air pollution through 2017, Beijing will expand its roadside emissions monitoring network to 150 monitoring points. Information from the current 22 roadside monitoring points helped lead to fines for excessive emissions for operators of about 5,000 vehicles in the first half of 2013. Penalties for excessive vehicle emissions could be increased from 500 Yuan ($82) to about 3,000 Yuan ($490) under proposed ordinances.

By the end of 2017, Beijing hopes to reduce fuel consumption by about 5 percent in the city. More than 4 million metric tons of gasoline and over 2 million metric tons of diesel fuel are currently consumed in Beijing annually, with diesel vehicles, particularly the more than 300,000 heavy trucks, contributing substantially.

As part of its plan, Beijing is aiming to hold the number of registered vehicles in the city to around 6 million by the end of 2017. It also aims to:

    • Introduce more controls on vehicles, particularly on those from outside the city, including expanding restrictions on which ones can enter inside the sixth-ring road (which runs around the city about 10 to 12 miles from the center) on certain dates and times;
    • Promote the use of alternative fuel vehicles to reduce air pollution;
    • Upgrade vehicle emissions standards to the equivalent of Euro 6 or tighter by 2016, add onboard refueling vapor recovery and further tighten fuel quality standards; and
    • Scrap about 1 million older vehicles that do not meet current tailpipe and fuel quality standards.

Other measures being considered include congestion fees and progressive parking pricing. These are in a study phase and it is uncertain when or if they would be implemented by 2017.

Beijing also plans to increase pollution discharge fees for sulfur dioxide and nitrogen oxides emissions and to begin charging pollution fees for volatile organic compound emissions. Environmental impact assessments for future projects in Beijing will need to include estimates of these emissions. Beijing hopes to establish an emissions trading system for these pollutants by the end of 2014.

Beijing will attempt to reach a goal of zero growth in the number of cars on its roads by the end of 2017. It plans to accomplish this, in part, by requiring the retirement of older vehicles that do not meet current exhaust and fuel standards and by limiting the number of license plates it issues each month. Starting next year (2015), the city plans more restrictions on which vehicles can be used within the fifth-ring and sixth-ring roads, including cars registered both in Beijing and elsewhere.

By the end of 2014, all new heavy-duty diesel vehicles will be required to install devices to trap particulate matter and to meet Beijing V tailpipe emission standards. Beijing also will implement plans to encourage the use of new-energy and cleaner energy vehicles, including those using natural gas, with an aim of having 200,000 such vehicles—particularly for public transportation—in use by the end of 2017.

By the end of 2015, all large cities in the three main air pollution control areas will be expected to have switched to China V gasoline and diesel fuel (the China equivalent to Euro V), which has a maximum sulfur content of 10 parts per million. China V gas is already being rolled out in several cities in those regions. China IV diesel fuel and gasoline with 50 ppm maximum sulfur content will be required nationwide by the end of 2014. China V diesel fuel and gasoline with 10 ppm maximum sulfur content will be required nationwide by the end of 2017.

Barriers to progress in China

Policy and political barriers

MEP lacks the authority to set fuel standards:While MEP is the lead agency for developing and enforcing vehicle emission standards and has proposed limits for toxics in fuels (e.g., benzene in gasoline), it does not have the clear authority to specify fuel quality parameters even if those parameters affect vehicle emissions. With MEP having no direct control of the stringency and implementation timeline of fuel quality standards, it has been unable to implement the systems approach and up until recently it has been unable to develop and implement a coherent vehicle emissions standards roadmap.

The technical committee that sets fuel standards is dominated by industry representatives: The development and management of fuel quality standards is led by the National Petroleum Products and Lubricants Standardization Committee (which is called TC280), a committee managed by the Standardization Administration of China (SAC), and a subcommittee under TC280 is dedicated to development of the fuel specifications. The secretariat organization of TC280, is the Research Institute of Petroleum Processing (RIPP), a research division of Sinopec, one of the largest oil companies in China. RIPP is responsible for staffing and managing TC280 and its subcommittee, as well as for drafting fuel specifications. Oil industry representatives and experts close to the industry dominate TC280 and its subcommittee—only three out of the 43 members in TC280 represent environmental and automobile interests and three out of the 30 members of the subcommittee are MEP or auto representatives. Such a small representation from the MEP and auto industry compromises the ba lance of the discussions on setting new standards due to the outsized influence of the oil industry’s perspective.

Financial barriers

Refineries may not recoup capital investment due to fuel price control:Retail prices of gasoline and diesel have always been set by the central government in China. Without a market pricing mechanism, it is difficult for the oil industry to recoup capital investments on refinery upgrades (such as adding desulfurization capacity at refineries) by passing on the higher production costs to consumers. Prior to its implementation, US EPA estimated the annual capital investment cost for meeting the ultra-low sulfur fuel requirements (15-ppm sulfur gasoline and diesel) would be USD 2.15 billion (15 billion RMB) in 2004 and USD 2.49 billion (17.5 billion RMB) in 2005. US refineries were able to raise prices of ultra low sulfur gasoline and diesel to recover investments for the desulfurization units. The incremental price was small compared to the variation in fuel price due to fluctuations in oil prices. To solicit industry’s support for setting more stringent fuel standards, MEP needs to explore ways to provide financial support for refinery upgrades.

Technical barriers

Limited technical expertise and data compared to the industry: There is a small team at MEP (including five staff in CRAES and two staff in VECC) working on fuels-related research and regulatory work and a laboratory in CRAES that performs fuel testing. But compared to the oil industry, MEP has far less expertise and technical capability, particularly on evaluating the emission implication of various fuel compositions, which is essential for recommending standard specifications. In addition, MEP has limited access data on refinery capacity and can only rely on the industry’s analysis of the cost and technical implications when considering adopting more stringent standards.

Lessons Learned from China’s Experience

A comprehensive clean vehicles program requires close coordination between vehicles and fuel quality – vehicles and fuels are a system.

Strong and innovative local actions can pave the way for strong national actions.

India's Progress in Addressing Clean Fuels and Vehicles

India's Progress in Addressing Cleaner Fuels and Vehicles


Map of India

Vehicular emission norms in India were first introduced in 1991 and tightened in 1996, when most vehicle manufacturers had to incorporate technologies such as catalytic converters to reduce exhaust emissions in the National Capital Region (NCR) and other major cities. This necessitated the use of lead free and lower sulfur fuels. Initially, refineries supplied lead free gasoline only to the cities where catalysts were required; because unleaded fuel was only available in limited areas for some time, many catalytic converters were destroyed by lead poisoning as vehicles drove out of those areas and were misfueled.

In India, automotive fuels are produced in accordance with Bureau of Indian Standards (BIS) standards. These standards are amended from time to time to meet environmental as well as other quality aspects and are mandatory. Fuel specifications based on environmental consideration were requested for the first time by the Ministry of Environment & Forests in April 1996 for achievement by 2000. These standards mandating lead free gasoline were incorporated in the BIS 2000 standards. Further, based on the Supreme Court order of April 1999, the Ministry of Surface Transport (MoST) notified Bharat Stage-I (BIS 2000) and Bharat Stage-II vehicle emission norms broadly equivalent to Euro I and Euro II, respectively,  for introduction in entire India and NCR respectively.

Auto Fuel Policy 2003

In response to the Supreme Court, the Ministry of Petroleum & Natural Gas created an Expert Committee on 13th September 2001 to recommend an Auto Fuel Policy for the country including the major cities. The Expert Committee submitted their report to the Government of India in August 2002 and based on its recommendations, MoP&NG released the “Auto Fuel Policy” in October 2003. In accordance with this policy, starting from 2005, fuel conforming to BS III norms (maximum sulfur content for gasoline of 150 ppm and diesel of 350 ppm) was introduced in 13 major cities, while BS II fuel (maximum sulfur content of 500 ppm) was made available elsewhere in the country. From April 2010, BS IV fuel (maximum sulfur content of 50 PPM for both gasoline and diesel) was implemented in 13 major cities and BS III fuel made available in the rest of the country from September 2010.

For light duty vehicles and trucks, Bharat Stage-II emission norms were mandated across the entire country from April I, 2005 to be upgraded to Euro III equivalent emission norms on April 1, 2010.  In the major cities Euro III equivalent emission norms were mandated from April 1, 2005 and Euro IV equivalent from April 1, 2010.

For new 2 and 3 wheelers, Bharat Stage-II emission norms went into effect from April 1, 2005. Euro III equivalent emission norms were encouraged from April 1, 2008 but mandatory not later than April 1, 2010.

The New Expert Committee

The Auto Fuel Policy (2003) had envisaged that the Policy undergo periodic revisions. Technological and other changes which take place over time were to be incorporated in the policy framework. Unfortunately, this plan was ignored for many years until 2013 when environmental pressures built up sufficiently that it was finally felt necessary to initiate a process to develop an Auto Fuel Vision & Policy for the country which would lay a clear roadmap to the year 2025. Accordingly, the Ministry of Petroleum & Natural Gas on 19 December 2012 constituted a new Expert Committee to prepare a “Draft Auto Fuel Vision & Policy 2025”.

The terms of reference for the Expert Committee included:

  1. Recommend a road-map for auto fuel quality up until 2025 for the country, taking into account the achievements under the last Auto Fuel Policy, the emission reductions of in-use vehicles, the growth of vehicles and the supply and availability of fuels, and
  2. Recommend vehicular emission norms for various categories of vehicles and a roadmap for their implementation.

Earlier this year (2014), the Expert Committee completed its work and recommended the following:

Fuels Road Map

For vehicles with four or more wheels, the Committee recommended a gradual expansion of the sale of BS IV vehicles as the sale of BS IV fuel expands and be mandatory nationwide by April 2017. BS V emission norms should apply to all new models of four or more wheeled vehicles from April 1, 2020 and for continuing models before April 1, 2021. No emission norms were recommended for BS VI by the Committee. However, conceptually the committee noted that the BS VI emission regime could become applicable with effect from 1 April 2024 for all classes of vehicles thus giving a gap of four years to the automobile manufacturers for upgrading and adjusting their technology, design and standards.

Vehicle Emissions Road Map

For vehicles with four or more wheels, the Committee recommended a gradual expansion of the sale of BS IV vehicles as the sale of BS IV fuel expands and be mandatory nationwide by April 2017. BS V emission norms should apply to all new models of four or more wheeled vehicles from April 1, 2020 and for continuing models before April 1, 2021. No emission norms were recommended for BS VI by the Committee. However, conceptually the committee noted that the BS VI emission regime could become applicable with effect from 1 April 2024 for all classes of vehicles thus giving a gap of four years to the automobile manufacturers for upgrading and adjusting their technology, design and standards.

On July 4, 2014, India finalized the fourth stage of emission standards for motorized two wheeled vehicles. The Bharat Stage (BS) IV standards will go into effect for type approval of new motorcycle models in April 2016, and for all motorcycle models in April 2017. The new standards tighten the HC+NOx emission limits compared with the existing BS III standards by 23%–60%, depending on motorcycle category. The other significant change to the regulation is the adoption of the Worldwide Harmonized Motorcycle Test Cycle (WMTC) as the mandatory test cycle. With this change, India has harmonized the testing cycle as well as the definition of motorcycle categories as per United Nations Economic Commission for Europe (UNECE) Global Technical Regulation 2 (GTR-2). In addition, the new regulation establishes the first evaporative emission standards for two-wheelers in India. Lastly, BS IV establishes that crankcase emissions form BS IV motorcycles are prohibited from release into the atmosphere.

The Committee recommends that BS V Emission norms for two wheelers be applicable for new models from April 1, 2020 for new models and for continuing models within one year thereafter.

The committee also recommended a similar schedule for the implementation of BS IV and BS V standards for both gasoline/ CNG/Auto LPG and diesel fuelled three wheelers.

The Expert Committee has completed its report and submitted it to the newly elected Prime Minister for consideration by the new government.  The matter is pending.

Lessons Learned From India's Experience

National policies regarding fuel quality are critically important.

A Vehicles and Fuels Roadmap laying out a long term strategy is in everyone’s interest so investment schedules can be optimized.

Such a roadmap needs to be periodically reviewed and updated as new information becomes available and as circumstances change.

Automobile Emissions in the United States and Europe

Automobile Emissions in Europe


Map of Europe

Automobile emissions regulations in Europe have been developed in least three arenas: the individual Member States, the European Community (now the EU), and the United Nations Economic Commission for Europe (UNECE).

During the 1950s and 1960s, efforts were under way in Europe as well as in the United States to deal with motor vehicle air pollution. France and Germany were especially active during this period, working independently toward emissions test procedures and emissions standards. The French organization Union Technique de l’Automobile du Motocycle et du Cycle (UTAC) was, for example, working on a driving cycle based on city driving in Paris.

One of the primary purposes of the European Economic Community (EEC), since the Treaty of Rome in 1957, was the elimination of trade barriers among the Member States. For many years, Directorate General III of the European Commission was responsible for harmonization within the internal market. It could develop directives on motor vehicle standards and, with the unanimous agreement of the other Directorates General, could send them forward to the Council of Ministers and the Parliament for approval. Once a directive was adopted and transposed into the national laws of each Member State, a Member State was obliged to accept an approved vehicle from another Member State and must issue a harmonized certificate for that vehicle.

The UNECE deals with economic issues as well as transportation and traffic questions, pursuant to the 1958 Geneva Agreement concerning the adoption of uniform conditions of approval and reciprocal recognition of approval for motor vehicle equipment and parts (335 United Nations Treaty Series 211, as amended). Transportation matters are handled by the Inland Transportation Committee, with Subcommittee One dealing with road traffic. Under this subcommittee, the Working Party on Pollution and Energy (previously known as Working Party 29) is responsible for motor vehicle regulations, with the Groupe des Rapporteurs pour la Pollution et l’Energie (GRPE) responsible for the development and evolution of all emissions control legislation and related subjects.

As France and Germany developed their motor vehicle standards, officials at the European level recognized the potential for individual countries proceeding unilaterally to create a patchwork of regulations that would act as a barrier to trade. In late 1965, WP 29 of the UNECE began an effort to define a European driving cycle. To lead that and other efforts in this emerging field, WP 29 created an expert working group on automobile pollution, GRPA (subsequently renamed GRPE). After investigations and negotiations, especially among the French, Germans, and British, in January 1967 the European Driving Cycle was accepted by the GRPA, and it was sent forward to WP 29 in March of that year.

While discussions continued in Geneva (UNECE) and Brussels (EEC), pressure was building in the Member States to take action. A German draft regulation announced on January 1, 1968, called for idle CO controls and crankcase controls in 1969 and emissions controls under driving conditions in 1970. Other countries became increasingly concerned regarding the potential for these regulations to effectively become barriers to trade within Europe. Other factors confounded this concern. Some European manufacturers were active in the U.S. market, but those that were not expected that having to adopt U.S. procedures or standards could place them at a competitive disadvantage. And European manufacturers and markets were quite diverse, with some focused almost exclusively on small cars and others only on large cars; the form of the standard could have differential effects by size of car.

A race against time ensued because of the German plans. If a UNECE regulation on vehicle emissions were adopted and an EEC directive based on it were subsequently issued before the German requirements went into effect, the German regulators agreed that their requirements would be made moot. If not, the German regulation would become national law, and each country would be free to develop its own requirements. In fact, with less than two months to spare, UNECE Regulation 15, or ECE R 15, was published. It went into effect on August 1, 1970, following the adoption of the EEC Directive on March 20, 1970, Directive 70/220/EEC. Thus the German regulation, which would have become effective on October 1, 1970, was superseded.

Following the initial development of the ECE R 15 requirements, a series of gradual steps to lower emissions was introduced. The second step, calling for a 20% reduction in CO and a 15% reduction in HC, entered into force on October 1, 1975 (ECE R 15, series 1). Next, restrictions were imposed for the first time on nitrogen oxides on October 1, 1977 (ECE R 15, series 2). A further modest step went into effect on October 1, 1979, when ECE R 15, series 3, called for a 12% to 19% reduction.

This trail of events set the process in place that effectively constrained the pace and stringency of European motor vehicle emissions regulation for the next 20 years. Two critically important features characterized the development of European regulations during this period. First, for the “Common Market” countries of the EEC, the development of emissions directives focused much more on ensuring that barriers to free trade did not occur than it did on protecting the environment and public health. Second, because unanimous agreement was required by all Member States of the EEC, the pace of regulation was in effect set by the least aggressive Member State rather than by the limits of technological feasibility or environmental need.

Role Played by Lead in Gasoline

To illustrate these transatlantic institutional differences, consider the issue of lead (Pb) in gasoline. In the United States in early 1971, it was already apparent that catalytic converters requiring lead-free gasoline were likely to be the dominant technology of choice to comply with the 1975 emissions standards. EPA initiated steps to phase out the use of leaded gasoline and to ensure that lead-free fuel would be widely available before 1975 model-year cars entered the marketplace. Several European (including German) vehicle manufacturers that were active in the U.S. market were also working on catalyst technology. In 1971, Germany adopted its “Lead in Gasoline Law,” which reduced the lead content to 0.4 grams/liter (g/l) from January 1, 1972, and to 0.15 g/l from January 1, 1976. Because of concerns that Germany would mandate lead-free fuel and create a barrier to trade, the EEC then issued a Directive that prohibited any member of the European Common Market from mandating fuel with less than 0.15 grams of lead per liter. In other words, the result in Europe was no lead-free fuel, and hence no catalytic converters were allowed. This prohibition on lead-free fuel clearly delayed progress in Europe for at least another decade. By contrast, the United States phased out lead in gasoline during the 1970s and 1980s—a more precautionary approach against the risks posed by lead exposure such as cognitive impairment in children.

Breaking the European Logjam

Public concern about motor vehicle air pollution in Europe continued to build throughout the 1980s, and individual Member States began to consider ways to get around the restrictions and weak standards of the EEC and ECE. Several European manufacturers were producing much cleaner vehicles for the U.S. market than for their home market, and the European public began demanding these cleaner technologies. The issues came to a head with the growing evidence showing serious damage to the Black Forest in Germany and Austria and other signs of ecological deterioration. As knowledge of these technological improvements in cars spread, and as the adverse effects of motor vehicle pollution became more widely recognized, more and more people across Europe began demanding the use of these systems in their countries. During the mid-1980s, Austria, the Netherlands, and the Federal Republic of Germany adopted innovative economic incentive approaches to encourage purchase of low-pollution vehicles. Sweden and Switzerland—not members of the Common Market at that time and therefore not legally constrained by its Directives—decided to adopt mandatory requirements based on the use of lead-free fuel and catalytic converters.

A key breakthrough occurred on May 16, 1984, when the European Commission proposed that Member States beallowedto mandate the availability of unleaded gasoline by January 1986; it also mandated that unleaded gasoline must be available in every Member State by 1989. Thus widespread availability of unleaded fuel; mandatory requirements for U.S.-type emissions standards in some countries outside the Common Market such as Austria, Sweden, and Switzerland; and economic incentives encouraging U.S.-type control technology in Germany and the Netherlands resulted in large numbers of catalyst-equipped cars emerging across Europe as the decade came to a close.

In 1990, the European Council of Environmental Ministers, in what became known as the Consolidated Directive, reached unanimous agreement to require all new models of light-duty vehicles by 1992/1993 to meet emissions standards roughly equivalent to U.S. 1987 levels. See tables following on EU Emissions Standards.          

Specifically, the ministers decided to do the following:

  • require all light-duty vehicles to meet emissions standards of 2.72 grams per kilometer (g/km) CO, 0.97 g/km of HC plus NOx, 0.14 g/km of particulates for type approval, and 3.16 g/km CO, 1.13 g/km for HC plus NOx, and 0.18 g/km particulates for conformity of production;
  • require the Commission to develop a proposal before December 31, 1992, that, taking account of technical progress, required a further reduction in limit values;
  • have the Council decide before December 31, 1993, on the standards proposed by the Commission; and
  • Allow Member States, prior to 1996, to encourage introduction of vehicles meeting the proposed requirements through “tax systems” that include pollutants and other substances in the basis for calculating motor vehicle circulation taxes.

Since the adoption of the consolidated Directive, Europe has moved quickly and aggressively to further tighten its requirements for clean vehicles and fuels. The first Auto-Oil program started in the early 1990s led to the adoption, in 1998, of the Euro 3 emission standards for new passenger cars and light commercial vehicles; these standards have been mandatory since January 2000.

The European Commission intended to use the second Auto-Oil program to investigate and confirm the Euro 4 emission standards, taking into account the likely improvements in emission control technology between 1998 and 2005, when Euro 4 was intended to become mandatory for new vehicles. However, the European Parliament and the Council decided to fix the Euro 4 emission standards at the same time as Euro 3 with the result that the second Auto-Oil program effectively focused on a range of additional measures that Member States might wish to apply where air quality problems due to road transport persisted.

In addition, Euro 3 introduced new requirements covering:

  • a cold start emission test carried out at –7 Celsius with specific limits for hydrocarbons and carbon monoxide;
  • in-use compliance checking to ensure that vehicles continue to achieve their type-approved emissions performance up to 100,000 km in the case of Euro 4;
  • a revised test procedure for evaporative emissions to better reflect a 24-hour daily temperature profile;
  • requirements for on-board diagnostic systems, and
  • inclusion of start-up emissions in the test – previously the first 40 seconds was not sampled.

The use of tax incentives by some of the Member States stimulated manufacturers to provide Euro 4 cars earlier than the mandatory date of 2005; similarly tax incentives were used by some member states to stimulate the early introduction of lower sulfur fuels.

Some Member States continued to put pressure on the Commission to come forward with new emission standards that were more stringent than Euro 4 to deal with their continuing air quality concerns, especially regarding diesel cars. It became clear that future emission standards for road vehicles must form an important part of the overall Clean Air for Europe (CAFE) strategy that was being developed to help achieve future EU air quality. For cars, the Environment Council of 18-19 December 2000 reported its conclusions on the second Auto-Oil program and noted the following:
“The Council supports the opinion put forward in the Commission communication concerning the need for further action on particulate matter, nitrogen oxides and tropospheric ozone.”
The Council invited the Commission to:

  • Encourage the progressive and harmonized introduction of fuels whose characteristics allow for the optimization of new technologies for the post-treatment of emissions and of new engine types;
  • Make continued efforts to significantly reduce nano-particle emissions;
  • Bring the provisions on limit values for diesel engines – for example, on emissions of nitrogen oxides (NOx) – closer to the provisions for gasoline engines;
  • Start technical work and the necessary studies to assess the feasibility of a new phase in the reduction of limit values for emissions which could come into force by 2010;
  • Review the latest developments of the new propulsion technologies, and to submit a report to the Council as soon as possible.

In short the Council asked the Commission to continue the work of further reducing emission from motor vehicles, in particular NOx and nano-particle emissions.

The European Parliament and the Council had decided to set the Euro 4 emission standards back in 1998. The political aim of Euro 4 had been to require the use of particulate filters on new diesel cars. However, engine controls improved, and high pressure common rail diesel systems became commonplace with the result that the Euro 4 emission limits were able to be met without the use of a particulate filter. Such vehicles would also qualify for tax incentives in those Member States offering such incentives.

Some manufacturers chose to take a “green line” and equip at least their larger diesel cars with particulate filters of one type or another.

The issue of fuel quality remained important and the EU mandated very low-sulfur gasoline and diesel (less than 10 ppm sulfur) from 2009 to allow the technology necessary to achieve lower pollutant emissions and improvements in CO2, which was becoming a high priority in Europe. Such fuels were also to be widely available by 2005 to allow the use of advanced aftertreatment technologies such as catalyzed diesel particulate filters and NOx adsorbers (especially for GDI) by some vehicles meeting Euro 4 requirements.

As a result of this effort, Euro 6 limits and requirements are being phased in across Europe at this time with all road fuels meeting a 10 ppm sulfur limit.

Automobile Emissions in the United States

Automobile Emissions in the United States


Map of USA

In 1960, California adopted legislation that called for the installation of pollution control devices as soon as three workable control devices were developed. In 1964, the state was able to certify that three independent manufacturers of emission control equipment had successfully developed such devices, which triggered the legal requirement that new automobiles must comply with California’s standards beginning with the 1966 model year. Soon afterward, the major U.S. domestic vehicle manufacturers announced that they too could and would clean up their cars with technology they had developed in house, thus eliminating the need for the independently developed devices.

Subsequent to California’s pioneering efforts, and as a result of recognition of the national nature of the automobile pollution problem, in 1964 Congress initiated federal motor vehicle pollution control legislation. As a result of the 1965 Clean Air Act Amendments, the 1966 California auto emissions standards were applied nationally in 1968.

In December 1970, the Clean Air Act was amended by Congress “to protect and enhance the quality of the nation’s air resources.” Congress took particular notice of the significant role of the automobile in the nation’s effort to reduce ambient pollution levels by requiring a 90% reduction in emissions from the level previously prescribed in emissions standards first for 1970 models for carbon monoxide (CO) and hydrocarbons (HC), and then for 1971 models for nitrogen oxides (NOx). Congress clearly intended to aid the cause of clean air by mandating levels of automotive emissions that it hoped would essentially remove the automobile from the pollution picture.

In many ways, the serious effort to control motor vehicle pollution can be considered to have begun with the passage of the landmark 1970 law. By including the stringent “technology forcing” requirements in the law and providing only very limited flexibility to EPA in relaxing these requirements, it forced the manufacturers to work aggressively toward compliance, because only Congress itself could provide relief. In addition, the law provided EPA with broad authority to implement the requirements, including provisions to mandate a recall of vehicles whenever “a substantial number of properly maintained and used” vehicles failed to meet standards in use over their useful lives, and to modify fuel quality—including the level of lead (Pb) in gasoline—if necessary to enable compliance.

This latter authority was especially critical, because the principal technology that emerged to enable compliance with the emissions standards was the catalytic converter—a technology that could not withstand lead additives. (Lead had been added to gasoline since the 1920s to “improve” combustion.) Finally, the 1970 law grandfathered in the California motor vehicle pollution control program and left that state with the unique authority (subject to EPA approval) to set its own standards and regulations for vehicle emissions. This proved critical over the years that followed, as California—suffering from the most serious vehicle-related air pollution problem in the country—consistently pushed the technology envelope over the next four decades, something it continues to do to this day.

In 1977, the CAA was “fine-tuned” by Congress, which delayed and slightly relaxed the auto standards under pressure from the vehicle industry. In doing so, though, Congress authorized the states to adopt either the federal EPA motor vehicle emissions standards or the California standards (thereby yielding two car designs that the manufacturers would have to produce), but Congress prohibited the states from setting any other standards that would require the creation of a so-called “third car.” The 1977 amendments also expanded the law with new requirements on controlling evaporative emissions and by imposing similarly stringent emissions requirements on heavy-duty trucks. More recently, Congress passed the 1990 Clean Air Act Amendments, further expanding EPA’s authority to regulate off-road vehicles and fuels. Also, EPA has issued a series of increasingly stringent regulations under the broad authority granted to it under the clean air law.

As a result of these requirements, substantial and rapid improvements in vehicle emissions have occurred over the past 40 years.

Shortly after the 1970 law went into effect, a gradual phase-out of the use of lead in gasoline was initiated, which allowed auto manufacturers to introduce lead-intolerant catalysts on most 1975 model-year cars. Further tightening of the NOx standards, first in California and then across the country in the early 1980s, accelerated the introduction of advanced electronic controls, which also enabled improvements in fuel economy during this same period. By the mid-1980s, stringent particulate matter (PM) standards were also introduced for diesel cars. Following the 1990 Clean Air Act Amendments, a further reduction in all of the pollutants was phased in throughout the 1990s including control of running loss and multiple diurnal emissions as well as the introduction of onboard refueling vapor recovery (ORVR).

Adoption of Cleaner Vehicles Programs

While Congress was in the late stages of the debate regarding what became the 1990 Clean Air Act Amendments, two significant events occurred:

In September 1990, California adopted the Low Emissions Vehicle (LEV) Program, which was distinctive in several important respects:

  • It provided flexibility to manufacturers by allowing them to certify vehicles meeting several distinct categories or sets of emissions standards (called “bins”) as long as their fleet sales on average complied with an overall standard for non-methane organic gases (NMOGs), which declined year by year throughout the 1990s.
  • It created a new category of vehicles, zero-emitting vehicles (ZEVs), in an effort to force the vehicle industry to devote significant resources to developing and introducing into the marketplace vehicles that effectively did not rely on the internal combustion engine. This arguably resulted in the introduction first of electric cars, then of hybrid electric cars, and is soon leading to commercially available fuel-cell-powered vehicles.
  • It provided special credits for vehicles with very low exhaust and evaporative emissions, PZEVs.
  • It also specifically linked vehicles and fuels, and it forced the introduction of “reformulated” gasoline with reduced sulfur levels, lower volatility, and other changes in composition.

Just as California was adopting the LEV program, New York became the first state that used Section 177 of the 1977 Clean Air Act Amendments to adopt California’s vehicle emissions standards. Subsequently, a number of other states have also adopted the California requirements.

As a backdrop to all these developments, air quality issues in the United States, although improved, remained widespread and serious. A growing body of public health studies—especially epidemiologic evidence of thousands of fatalities per year in areas with higher air pollution levels—impelled EPA to tighten health-based air quality requirements for both ozone (or photochemical smog) and PM.

Additional Elements of the Program

The broader authority provided to EPA under the 1990 Clean Air Act Amendments, the surge in California to push the air pollution technology envelope even further, and the healthy cooperation and occasional competition between EPA and California to mandate clean vehicles and fuels have all combined to bring several additional important elements into the U.S. program. These include the following:

  • An unanticipated a new class of vehicles called sport utility vehicles (SUVs) emerged, soon representing almost half the U.S. light-duty vehicle market. SUVs were legally classified as light trucks, which were traditionally covered by more lenient emissions standards. Today’s latest emissions standards now require light trucks to meet the same requirements as cars.
  • Recognizing the growing importance of evaporative hydrocarbons, EPA has substantially broadened and tightened evaporative emissions requirements including the addition of onboard refueling vapor recovery systems that capture the emissions from the vehicles fuel tank during refueling as well as the addition of multiple day diurnal and running loss control.
  • Light-duty diesel vehicles had been allowed to meet a more lenient NOx standard than their gasoline counterparts; both California and EPA now require diesel and gasoline vehicles to meet the same standards.
  • The close linkage between vehicle emissions requirements and fuel quality is now recognized and established, with the result that very low levels of sulfur in both gasoline and diesel fuel are being mandated not only in California, but across the entire country.
  • Heavy-duty trucks, which traditionally had more lenient emissions requirements, have been forced to introduce very advanced after-treatment technologies by 2010.
  • Nonroad vehicles, especially diesel-fueled farm and construction equipment, as well as ships and locomotives, are required to meet stringent emissions standards similar to the limits covering on-road heavy-duty vehicles, with a lag of only a few years after on road vehicles.

Tier I standards adopted in 1991 were tightened by Tier II standards adopted in 2004.  Most recently, on March 3rd, 2014, the U.S. Environmental Protection Agency (EPA) finalized a further tightening of emission standards for vehicles and gasoline, reducing evaporative standards for smog-forming volatile organic compounds and exhaust standards for NOx by an additional 80 percent, establishing a 70 percent tighter particulate matter standard and virtually eliminating fuel vapor emissions. The final fuel standards will reduce gasoline sulfur levels by more than 60 percent – down from 30 to 10 parts per million (ppm) in 2017. EPA found that reducing sulfur in gasoline will provide significant and immediate health benefits because every gas-powered vehicle on the road built prior to these standards will run cleaner – cutting smog-forming NOx emissions by 260,000 tons in 2018.

show a comparison of the US/California Program and the EU Program