Once common throughout the industry on a variety of vehicle types, this method of construction is now largely limited to pickups and SUVs. As the name suggests, these vehicles use two separate components for the vehicle’s frame: a ladder-type frame sits under the body itself.
This ladder frame resists twisting better than a unibody vehicle, so it’s generally preferred for towing or carrying heavy loads and for aggressive off-road driving. It’s also easier to modify these vehicles’ suspensions to make room for additional wheel travel or larger tires and wheels.
This method was also preferred in the earlier days of the automobile because automakers could make annual changes to their vehicles’ body styles while keeping the same frame underneath; they could also use distinct bodies on the same frames.
But as the industry increasingly shifted to the unibody setup, fewer and fewer vehicles stayed with this old-school setup. Aside from today’s SUVs and pickups that continue down the body-on-frame path, some large sedans were the most recent holdouts. Notably, Ford’s Crown Victoria and Lincoln’s Town Car — workhorses of livery services for years — rode on Ford’s Panther rear-wheel-drive, body-on-frame platform until they were discontinued in 2011.
