Vehicle size class

Vehicle size classes are series of ratings assigned to different segments of automotive vehicles for the purposes of vehicle emissions control and fuel economy calculation. Various methods are used to classify vehicles; in North America, passenger vehicles are classified by total interior capacity while trucks are classified by gross vehicle weight rating (GVWR). Vehicle segments in the European Union use linear measurements to describe size. Asian vehicle classifications are a combination of dimensions and engine displacement.

Vehicle classifications of four government agencies are in use in the United States: the United States Environmental Protection Agency (EPA), the National Highway Traffic Safety Administration (NHTSA as part of their NCAP program), Federal Highway Administration (FHWA), and the U.S. Census Bureau. The Insurance Institute for Highway Safety also has its own vehicle classification system that is used by most vehicle insurance companies in the U.S.

EPA size classes are defined in Federal Regulation, Title 40—Protection of Environment, Section 600.315-08 "Classes of comparable automobiles". This information is repeated in the Fuel Economy Guide. Passenger car classes are defined based on interior volume index (the combined passenger and cargo volume) and are as follows.

Trucks classes are defined by gross vehicle weight rating (GVWR). The administrator classifies light trucks (nonpassenger automobiles) into the following classes: Small pickup trucks, standard pickup trucks, vans, minivans, and SUVs. Starting in the 2013 model year, SUVs are divided between small sport utility vehicles and standard sport utility vehicles. Pickup trucks and SUVs are separated by car line on the basis of gross vehicle weight rating (GVWR). For a product line with more than one GVWR, the characteristic GVWR value for the product line is established by calculating the arithmetic average of all distinct GVWR values less than or equal to 8,500 pounds available for that product line.

Special purpose vehicles. All automobiles with GVWR less than or equal to 8,500 pounds and all medium-duty passenger vehicles which possess special features and which the administrator determines are more appropriately classified separately from typical automobiles.

Unlike the EPA, which groups automobiles by interior volume, the NHTSA groups cars for NCAP testing by weight class.

Developed in the 1980s, the Federal Highway Administration 13-category classification rule set is currently used for most federal reporting requirements and that serves as the basis for most state vehicle classification systems.

Source: Verification, Refinement, and Applicability of Long-Term Pavement Performance Vehicle Classification Rules, FHWA