Regulatory Announcement

EPA Proposes Tier 3 Motor Vehicle 

Emission and Fuel Standards 

The U.S. Environmental Protection Agency (EPA) is issuing a 

proposed rule designed to reduce air pollution from passenger cars 

and trucks. Starting in 2017, Tier 3 would set new vehicle emissions 

standards and lower the sulfur content of gasoline, considering the 

vehicle and its fuel as an integrated system. 

 The proposed vehicle standards would reduce both tailpipe and evaporative 

emissions from passenger cars, light-duty trucks, medium-duty passenger 

vehicles, and some heavy-duty vehicles. 

 The proposed gasoline sulfur standard would make emission control systems 

more effective for both existing and new vehicles, and would enable more 

stringent vehicle emissions standards. Removing sulfur allows the vehicle’s 

catalyst to work more efficiently. Lower sulfur gasoline also facilitates the 

development of some lower-cost technologies to improve fuel economy and 

reduce greenhouse gas (GHG) emissions, which reduces gasoline consumption and saves consumers money. 

 The proposed tailpipe standards include different phase-in schedules that vary 

by vehicle class but generally phase in between model years 2017 and 2025. 

In addition to the gradual phase-in schedules, other proposed flexibilities 

include credits for early compliance and the ability to offset some higheremitting vehicles with extra-clean models. 

 The proposed fuel sulfur standards include an averaging, banking, and trading 

(ABT) program that would allow refiners and importers to spread out their 

investments through an early credit program and rely on ongoing nationwide 

averaging to meet the sulfur standard. EPA is also proposing flexibilities such 

as hardship provisions for extenuating circumstances, as well as flexibility provisions for small businesses (small manufacturers of Tier 3 vehicles and small 

refiners), small volume manufacturers, and small volume refineries. 

Office of Transportation and Air Quality 

EPA-420-F-13-016a 

March 2013 
Regulatory Announcement

 

 The Tier 3 program continues the successful transition that began with EPA’s Tier 2 

program, finalized in 2000, in which EPA treated vehicles and fuels as a system to reduce 

both gasoline sulfur and vehicle emissions. While there were claims at the time that the 

program would cause fuel prices to increase far in excess of EPA’s estimates and would 

result in closures and fuel supply shortages, the Tier 2 program was a success and resulted 

in gasoline sulfur reductions of up to 90 percent and enabled the use of new emission 

control technologies in cars and trucks with no serious negative impacts on the refining 

industry. EPA’s Clean Diesel Program similarly utilized a systems approach to reducing sulfur emissions from diesel fuels and enabling cleaner diesel technologies with the 

Highway Diesel Rule (finalized in 2001) and the Nonroad Diesel Rule (finalized in 2004) 

again with no serious negative impacts. Now that the U.S. refining industry routinely 

produces lower sulfur fuel products, new market opportunities for international fuel exports have opened up. 

EPA is proposing the Tier 3 standards to address public health issues that exist currently and are 

projected to continue in the future as requested in a May 21, 2010 Presidential memorandum. 

 Over 158 million Americans are currently experiencing unhealthy levels of air pollution 

which are linked with adverse health impacts such as hospital admissions, emergency 

room visits, and premature mortality. Motor vehicles re a particularly important source of 

exposure to air pollution, especially in urban areas. 

	The proposed vehicle emission standards combined with the proposed reduction of 

gasoline sulfur content would significantly reduce motor vehicle emissions, including 

nitrogen oxides (NOX), volatile organic compounds (VOC), direct particulate matter 

(PM2.5), carbon monoxide (CO) and air toxics. 

 Compared to current standards, the proposed non-methane organic gases (NMOG) and 

nitrogen oxides (NOX), presented as NMOG+NOX, tailpipe standards for light-duty 

vehicles represent approximately an 80% reduction from today’s fleet average and a 

70% reduction in per-vehicle particulate matter (PM) standards. Proposed heavy-duty 

tailpipe standards represent about a 60% reduction in both fleet average NMOG+NOX 

and per-vehicle PM standards. EPA is also proposing to extend the regulatory useful life 

period during which the standards apply from 120,000 miles to 150,000 miles. 

 EPA is also proposing that federal gasoline contain no more than 10 parts per million 

(ppm) of sulfur on an annual average basis by January 1, 2017. In addition, EPA is 

proposing to either maintain the current 80-ppm refinery gate and 95-ppm downstream 

caps or lower them to 50 and 65 ppm, respectively. The proposed Tier 3 gasoline sulfur 

standards are similar to levels already being achieved in California, Europe, Japan, South 

Korea, and several other countries. 

 Emission reductions from the Tier 3 program would lead to immediate air quality 

improvements that are critically important for states to attain and maintain the existing 

health-based National Ambient Air Quality Standard (NAAQS). In the absence of 

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Regulatory Announcement

 

 

 

 

 

 

 

 

additional controls such as the Tier 3 standards, many areas would continue to have air 

pollution levels that exceed the NAAQS in the future. 

 Tier 3 would also reduce exposure to vehicle pollution for the millions of people living, 

working, and going to school near major roads. 

Tier 3 is among the most highly cost-effective air quality control measures available. 

 The program would cost about a penny per gallon of gasoline, and about $130 per 

vehicle. The annual cost of the overall program in 2030 would be approximately $3.4 

billion; however, EPA estimates that in 2030, the annual monetized health benefits of 

the proposed Tier 3 standards would be between $8 and $23 billion. 

 By 2030, the Tier 3 standards would annually prevent: 

•	Between 820 and 2,400 premature deaths 

•	 3,200 hospital admissions and asthma-related emergency room visits 

•	 22,000 asthma exacerbations 

•	 23,000 upper and lower respiratory symptoms in children 

•	 1.8 million lost school days, work days and minor-restricted activities 

The proposed Tier 3 program is part of a comprehensive approach to reducing the impacts of 

motor vehicles on air quality and public health. 

 The Tier 3 proposal is harmonized with the California Air Resources Board (CARB) 

Low Emission Vehicle (LEV III) program so automakers could sell the same vehicles in 

all 50 states. 

 The Tier 3 proposal is aligned with and designed to be implemented over the same 

timeframe as EPA’s program for reducing greenhouse gas (GHG) emissions from lightduty vehicles starting in model year 2017. 

 Together, the Tier 3, light-duty GHG, and LEV III standards would maximize reductions 

in GHGs, criteria pollutants and air toxics from motor vehicles while streamlining 

programs and providing regulatory certainty and compliance efficiency. 

EPA has had extensive outreach and input from stakeholders during the development of the 

proposed Tier 3 standards. These stakeholders included auto manufacturers, oil refiners, manufacturers of vehicle emission control systems, fuel distributers, state/local governments and 

organizations, and environmental and public health groups. 

EPA welcomes your comments on this proposed rule. Further information on the public comment period may be found on EPA’s website (see For More Information below). All comments 

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Regulatory Announcement

should be identified by Docket ID No. EPA-HQ-OAR-2011-0135 and submitted by one of the 

following methods. 

You should consult the Federal Register notice for this proposal for more information about how 

to submit comments, when the comment period will close, and about where and when public 

hearings will be held. A copy of the Federal Register notice can be found on our website listed 

below: 

Internet: www.regulations.gov 


E-mail: A-and-R-Docket@epa.gov 


Mail: 


Environmental Protection Agency 

Air and Radiation Docket and Information Center (6102T) 

1200 Pennsylvania Avenue NW 

Washington, DC 20460 

Hand Delivery: 


EPA West building 


EPA Docket Center (Room 3340) 


1301 Constitution Avenue NW 


Washington, DC 


For More Information 

You can access the rule and related documents on EPA’s Office of Transportation and Air Quality 

(OTAQ) Web site at: 

www.epa.gov/otaq/tier3.htm 

For more information on this rule, please contact the U.S. Environmental Protection Agency, 

Office of Transportation and Air Quality at: 

E-mail: otaq@epa.gov 

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