Type means a class of vehicle distinguished by common traits, including design and purpose. Passenger cars, multipurpose passenger vehicles, trucks, buses, trailers, incomplete vehicles and motorcycles are separate types.
49 CFR § 565.22
Federal Motor Vehicle Safety Standards Definitions. Unless otherwise indicated, all terms used in this part that are defined in 49 CFR 571.3 are used as defined in 49 CFR 571.3.