The National Highway Traffic Safety Administration (NHTSA) may revise the technical and semantic definitions of cars and trucks over the next year. These decisions would affect rules about fuel economy and significantly impact the automotive industry. The NHTSA currently classifies SUVs, minivans, and certain car-truck hybrids as trucks for fuel economy purposes. If these vehicles were to be re-identified as cars, they would have to be made lighter and more fuel-efficient. Several car manufacturers expressed concern to the NHTSA that the reclassifications would hurt Detroit’s Big 3. Car-truck hybrids include DaimlerChrysler’s PT Cruiser, Ford’s Escape, and Honda’s CRV, which are all currently classified as trucks by the NHTSA. The NHTSA definitions were put in place in the 1970s when light trucks made up only 20 percent of the market. Light trucks presently comprise about 50 percent, mainly due to SUV sales. NHTSA said, “The functional distinction between cars and trucks . . . has broken down.” The NHTSA’s reevaluation follows the recent defeat in Congress of a proposal for stricter fuel-efficiency standards. The agency will decide by next April.