EPA and the National Highway Traffic Safety Administration (NHTS A) signed final rules on August 9, 2011, setting greenhouse gas (GHG ) and fuel economy standards for medium- and heavy-duty pickup trucks, delivery vehicles and tractor-trailers. The rules set standards for model years 2014 through 2018 and require manufacturers to improve fuel economy and GHG emissions by up to 20 percent for some models by 2018. Issued jointly by EPA and NHTS A, the rules amend 49 C.F.R. Parts 523, 534 and 535 and 40 C.F.R. Parts 85, 86, 600, 1033, 1036, 1037, 1039, 1065, 1066, and 1068, and will be effective 60 days after publication in the Federal Register.