The term “chassis” refers to a framework, or base, that supports something else. Electronic devices like televisions and computers typically have metal chassis on which the circuit boards and electronic components are mounted. In the automotive industry, the chassis is one of the main, structural design components. In that context, a chassis is essentially the metal “frame” component that is used in body-on-frame construction. The term “rolling chassis” refers to that frame plus the drivetrain, suspension, and other essential non-body components.
In automotive design, there are two basic construction techniques that are defined by which component provides the structural integrity of the vehicle. Those two styles are defined as using a “structural frame” or a “structural shell.” Vehicles that use body-on-frame designs have a “structural frame” that is composed of a frame, which itself is the main component of the vehicle’s chassis.
While the terms “frame” and “chassis” aren’t completely interchangeable, they do refer to more or less the same thing: the structural skeleton that the rest of the vehicle is built on. The frame is the actual metal structure that supports the coachwork, powertrain, and suspension, while the chassis is the frame plus any number of non-body components.
