The United States Environmental Protection Agency (EPA) Fuel Economy Regulations for 1977 and Later Model Year (dated July 1996) includes definitions for classes of automobiles.[1] Based on the combined passenger and cargo volume, large cars (full-size cars) are defined as having an interior volume index of more than 120 cu ft (3.4 m3) for sedan models, or 160 cu ft (4.5 m3) for station wagons.[2][3]