Environmental Protection Agency and Department of Transportation, National Highway Traffic Safety Administration: Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles
GAO-11-955R: Sep 30, 2011
GAO reviewed the Environmental Protection Agency (EPA) and Department of Transportation, National Highway Traffic Safety Administration's (NHTSA) new rule on greenhouse gas emissions standards and fuel efficiency standards for medium-and heavy duty engines and vehicles. GAO found that (1) these final rules establish a comprehensive Heavy-Duty National Program that will reduce greenhouse gas emissions and fuel consumption for on-road heavy-duty vehicles. NHTSA's final fuel consumption standards and EPA's final carbon dioxide (CO2) emissions standards are tailored to each of three regulatory categories of heavy-duty vehicles: Combination Tractors; Heavy-duty Pickup Trucks and Vans; and Vocational Vehicles. The rules include separate standards for the engines that power combination tractors and vocational vehicles. Certain rules are exclusive to the EPA program. These include EPA's final hydrofluorocarbon standards to control; and (2) EPA and NHTSA complied with applicable requirements in promulgating the rule.