The U.S. EPA and the NHTSA (National Highway Traffic Safety Administration) are proposing the first national standards for greenhouse gas emissions and fuel efficiency for heavy-duty trucks and buses. For combination tractors, the standards would begin in the 2014 model year and achieve up to a 20% reduction in CO2 emissions and 20% improvement in fuel efficiency by MY2018. The emissions standard would range from 64 to 116 g CO2/ton-mi and fuel consumption standards would range from 6.3 to 11.4 gal/1000 ton-mi. For heavy-duty pickup trucks and vans, there would be separate gasoline and diesel truck standards, starting in MY2014 and achieving up to a 10% reduction for gasoline vehicles and a 15% reduction for diesel vehicles by MY2018 (12 and 17% accounting for air conditioning leakage). Vocational vehicles would see standards starting in MY2014 with up to a 10% reduction in fuel consumption and emissions by MY2018. The emissions standards would range from 107 to 344 g CO2/ton-mi with fuel standards from 10.5 to 33.8 gal/1000 ton-mi. The cost of the program is approximately $7.7 billion, with possible benefits totaling $49 billion. It is projected to reduce GHG emissions by 250 million t and save 500 million barrels of oil over the lives of the vehicles produced within the first five years. A draft environmental impact statement (DEIS) on the proposal is available for review at http://www.nhtsa.gov/fueleconomy. Written comments on the DEIS are due to NHTSA by Jan. 3.