Unibody

Unibody, short for unitized body, is a vehicle construction method in which the body panels and structural frame are integrated into a single welded or bonded unit, rather than a separate frame with a body mounted on top. Structural loads from driving, cornering, and impacts are carried through the body shell itself, which is engineered with reinforced sections to handle those forces.

Unibody construction generally allows for lighter overall vehicle weight compared to a traditional body-on-frame design, since a single integrated structure can be engineered to avoid the redundant material of both a separate frame and a separately reinforced body. This weight advantage, combined with typically lower manufacturing costs at high production volumes, made unibody construction the dominant approach for passenger cars, and it has expanded into most crossovers and many modern SUVs.

Body-on-frame construction still persists in vehicles that prioritize heavy-duty towing, off-road durability, or the ability to easily swap different bodies onto the same frame, such as traditional pickup trucks and some body-on-frame SUVs. The tradeoff is generally that body-on-frame vehicles are heavier and can flex more under certain loads, while unibody vehicles tend to offer better ride comfort and handling but can be more complex or costly to repair after significant structural damage.