A
vehicle frame, also known as its
chassis, is the main supporting
structure of a
motor vehicle to which all other components are attached, comparable to the
skeleton of an
organism.
Until the 1930s, virtually every (motor) vehicle had a structural frame, separate from the car's body. This construction design is known as
body-on-frame. Since then, nearly all passenger cars have received unibody construction, meaning their chassis and bodywork have been integrated into one another. The last UK mass-produced car with a separate chassis was the
Triumph Herald, which was discontinued in 1971. However, nearly all
trucks, buses and
pickups continue to use a separate frame as their chassis.