Fuel-Efficient Fleets Act of 2006 - Amends federal transportation law to set forth certain phased-in minimum fuel economy standards for new federal fleet vehicles.
Authorizes the award of grants to assist states in purchasing vans, trucks, sport utility vehicles, minivans, or passenger automobiles that meet the new federal fleet vehicle fuel economy standards.
Subjects federal agencies to Buy American requirements requiring not less than 50% of newly purchased or leased federal fleet vehicles to be U.S. manufactured.