A truck's GVWR, or its gross vehicle weight rating, is the truck's maximum operating weight/mass. The gross vehicle weight rating is specified by the truck's manufacturer.
The GVWR is determined by including the maximum weight of the vehicle's chassis, body, engine, engine fluids, fuel, accessories, driver, passengers and cargo. The GVWR does not include the weight of any trailers. The United States Department of Transportation puts trucks into classes based on GVWR ranked from 1 to 8, with 1 being the smallest and 8 the largest. The classes help to determine commercial designation and safety regulations for the vehicle and also assist with registration.