Office of Transportation and Air Quality

EPA-420-F-14-010

March 2014

The U.S. Environmental Protection Agency (EPA) is finalizing an 

important rule designed to reduce air pollution from passenger 

cars and trucks. Starting in 2017, Tier 3 sets new vehicle emissions 

standards and lowers the sulfur content of gasoline, considering the 

vehicle and its fuel as an integrated system. The vehicle standards 

reduce both tailpipe and evaporative emissions from passenger cars, 

light-duty trucks, medium-duty passenger vehicles, and some heavyduty vehicles. The gasoline sulfur standard will make emission control 

systems more effective for both existing and new vehicles, and will 

enable more stringent vehicle emissions standards since 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 Tier 3 standards are closely coordinated with 

California’s Low Emission Vehicle (LEV III) standards as well as with 

EPA’s and California’s programs for GHG emissions from light-duty 

vehicles. EPA is setting these Tier 3 standards to address public health 

issues that exist currently and are projected to continue in the future. 

EPA’s action was requested in a May 2010 Presidential memorandum.

Clean Cars Program

In May 2009, President Obama requested EPA and the Department of Transportation (DOT) to develop new standards to reduce GHG emissions and improve fuel 

economy for cars and light trucks. EPA and DOT established the first set of coordinated GHG/fuel economy standards for model year (MY) 2012-2016 vehicles in 

Regulatory Announcement

EPA Sets Tier 3 Motor Vehicle Emission 

and Fuel Standards, Strengthens Clean 

Cars Program
Regulatory Announcement

2

April 2010, and a second set of standards for MY 2017-2025 in August 2012. These standards 

were based on extensive input from a wide range of stakeholders, with strong support from the 

auto industry, automotive suppliers, labor unions, state and local governments, consumer organizations, environmental and public health groups, and national security organizations. Taken 

together, the Administration’s clean car program will double the fuel economy of light-duty cars 

and trucks by 2025 - the first significant improvement in over three decades. Under the program, 

average new car and light truck fuel economy is expected to reach an average greenhouse gas 

performance of 163 grams per mile, equivalent to 54.5 miles per gallon by 2025, saving consumers 

$1.7 trillion at the pump—more than $8,000 per vehicle for a MY2025 vehicle—reducing oil 

consumption by 2.2 million barrels a day in 2025, and slashing greenhouse gas emissions by 

6 billion metric tons over the lifetime of the vehicles sold during this period. 

Comprehensive Approach

The 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 standard is aligned with and designed to be 

implemented over the same timeframe as EPA’s second phase of GHG standards for light-duty 

vehicles starting in model year 2017. 

Together, the Tier 3 and GHG programs provide significant environmental benefits and energy 

security to the nation, by maximizing reductions in GHGs, criteria pollutants and air toxics 

from motor vehicles, reducing costs to consumers, and providing automakers regulatory certainty 

and streamlined compliance. The standards will work together with California’s clean cars and 

fuels program to create a harmonized nationwide vehicle emissions program that enables automakers to sell the same vehicles in all 50 states. 

For More Information

You can access the Tier 3 final rule, regulations and related documents on EPA’s Office of 

Transportation and Air Quality (OTAQ) Web site at: 

www.epa.gov/otaq/tier3.htm

You can find background on the light-duty GHG program at:

www.epa.gov/otaq/climate/regs-light-duty.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