The Transportation Department and Environmental Protection Agency released new final rules that establish increasingly stringent fuel economy standards and much stricter greenhouse gas emission standards for 2012 through 2016 model-year vehicles.
Starting with 2012 model-year vehicles, the rules require automakers to improve fleet-wide fuel economy and reduce fleet-wide greenhouse gas emissions by approximately 5 percent every year. The National Highway Traffic Safety Administration (NHTSA) has established fuel economy standards that strengthen each year reaching an estimated 34.1 mpg for the combined industry-wide fleet for model-year 2016.
Because credits for air-conditioning improvements can be used to meet the EPA standards, but not the NHTSA standards, the EPA standards require that by the 2016 model-year, manufacturers must achieve a combined average vehicle emission level of 250 grams of carbon dioxide per mile. The EPA standard would be equivalent to 35.5 miles per gallon if all reductions came from fuel economy improvements.