EPA and the National Highway Traffic Safety Administration (NHTSA) have issued a final rule designed to reduce greenhouse gas (GHG) emissions and improve the fuel economy of light-duty vehicles. 75 Fed. Reg. 25,323 (05/07/10). The new standards apply to passenger cars, light-duty trucks and medium-duty passenger vehicles covering model years 2010 through 2016. According to the agencies, these vehicle categories are responsible for almost 60 percent of all U.S. transportation-related GHG emissions.

The standards will require the more widespread use of technologies that include “improvements to engines, transmissions, and tires; increased use of start-stop technology; improvements in air conditioning systems; increased use of hybrid and other advanced technologies; and the initial commercialization of electric vehicles and plug-in hybrids.” The final rule is effective on July 6, 2010. Industry groups filed a challenge to the standards the day they were published. Coal. for Responsible Regulation, Inc. v. EPA, No. 10-1092 (D.C. Cir. petition for review filed 05/07/10).