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Transportation and Climate Change Clearinghouse

Federal Programs Directory

Automotive Fuel Economy Program


In 1975, the U.S. Congress, responding to dramatic increases in petroleum prices, set minimum average standards for automobile fuel economy (i.e. the amount of fuel consumed by a vehicle per mile of travel). These standards were established under the Energy Policy and Conservation Act (EPCA) of 1975, and have subsequently been increased and expanded to cover most light trucks. Different standards are in place for automobiles and light trucks. The Corporate Average Fuel Economy (CAFE) program was established to determine vehicle manufacturer compliance with these standards.

Relationship to Climate Change

Most automobiles and light trucks are currently fueled with petroleum-based gasoline and diesel fuel. Carbon accounts for most of the mass of these fuels. When fuel is burned, as in an automobile engine, virtually all of the carbon in the fuel is released to the atmosphere as carbon dioxide, a key greenhouse gas. The CAFE program provides vehicle manufacturers with one incentive to sell more fuel-efficient vehicles automobiles and light trucks. There is considerable debate regarding CAFE's influence relative to, for example, fuel prices and consumer preferences, and regarding the broad impacts of CAFE.

DOT's Role

The Secretary of Transportation is required to administer a program for regulating the fuel economy of new passenger cars and light trucks in the U.S. market. The authority to administer the program has been delegated by the Secretary to the Administrator of National Highway Traffic Safety Administration (NHTSA). NHTSA's responsibilities in the fuel economy area include:

  1. Establishing and amending average fuel economy standards for manufacturers of passenger cars and light trucks, as necessary;
  2. Promulgating regulations concerning procedures, definitions, and reports necessary to support the fuel economy standards;
  3. Considering petitions for exemption from established fuel economy standards by low volume manufacturers (those producing fewer than 10,000 passenger cars annually worldwide) and establishing alternative standards for them;
  4. Preparing reports to Congress annually on the fuel economy program;
  5. Enforcing fuel economy standards and regulations; and
  6. Responding to petitions concerning domestic production by foreign manufacturers, and other matters.

Passenger car fuel economy standards were established by Congress for Model Year (MY) 1985 and thereafter at a level of 27.5 miles per gallon (mpg). NHTSA recently increased the standard for light trucks from the previous level of 20.7 mpg through MY 2004, to 21.0 in 2005, 21.6 in 2006, and 22.2 in 2007. In December 2007, Congress passed new rules requiring that these standards be increased such that, by 2020, the new cars and light trucks sold each year deliver a combined fleet average of 35 miles per gallon.

DOT shares responsibility for the CAFE program with the U.S. Environmental Protection Agency, which administers the testing program that generates the fuel economy data and determines the procedures for calculating the fuel economy values for CAFE.

Additional Information