Vehicle Fuel Economy and Greenhouse Gas (GHG) Emissions Standards

Vehicle manufacturers must meet fuel economy and GHG emissions standards for vehicles sold in the United States. The U.S. Department of Transportation’s (DOT) National Highway Traffic Safety Administration (NHTSA) regulates fuel economy standards, while the U.S. Environmental Protection Agency (EPA) regulates GHG emissions.

NHTSA’s Corporate Average Fuel Economy (CAFE) program and EPA’s light-duty vehicle GHG emissions program set standards for passenger cars, light-duty trucks, and medium-duty passenger vehicles. By Model Year (MY) 2025, these vehicles must meet an estimated combined average fuel economy of 48.7 to 49.7 miles per gallon or higher. The standards provide flexibility to manufacturers, including the ability to earn credits for alternative fuel vehicles. For information on the standards from MY 2017 to 2025, see the final rule in the Federal Register.

Additionally, fuel efficiency standards will increase by 2% per year for MY 2027 to 2031 passenger vehicles and MY 2029 to 2031 light-duty trucks. For more information on the standards from MY 2027 to 2031, see the NHTSA final rule.

NHTSA and EPA also regulate fuel economy and GHG emissions for on-road vehicles with a gross vehicle weight rating (GVWR) of 8,500 pounds or greater and the engines that power them. For MY 2014 to 2018 medium- and heavy-duty vehicles that are not already covered by the standards described above, manufacturers must meet increasingly stringent fuel economy and GHG emissions standards tailored to each of three main regulatory subcategories: combination tractors (also known as semi trucks); heavy-duty pickup trucks and vans; and vocational vehicles (such as delivery, refuse, and tow trucks; transit, shuttle, and school buses; and emergency vehicles). The standards provide flexibility, allowing for emissions and/or fuel consumption credits to be averaged, banked, or traded. For more information, refer to the final rule in the Federal Register.

For more information, see the EPA’s Regulations and Standards website and NHTSA’s CAFE website.

(Reference 40 CFR 85-86, 600, 1033, 1036-1037, 1039, 1065-1066, and 1068, 49 CFR 523, 531, 533-534, and 537-538, and 49 U.S. Code 329)