Amends federal transportation law to revise passenger automobile fuel economy standards (CAFE standards) to require that average fuel economy standards in effect for the preceding model year for a passenger automobile shall apply to such model year and beyond if the Secretary of Transportation does not prescribe new average fuel economy standards for a given model year. Authorizes the Secretary to prescribe regulations amending average fuel economy standards for passenger automobiles to a maximum feasible average fuel economy level that the Secretary decides automobile manufacturers can achieve in a model year based on one or more vehicle attributes related to fuel economy. (Currently, the Secretary can prescribe average fuel economy standards that the Secretary decides are the maximum feasible average fuel economy level for that model year). Eliminates the congressional approval requirement if the Secretary prescribes an amendment that makes an average fuel economy standard more stringent.
Directs the Administrator of the National Highway Traffic Safety Administration to conduct a study, and report the results to Congress and the Administrator of the Environmental Protection Agency, on the effects of the requirement of separate fuel economy calculations for domestic and foreign automobiles.