Originally Posted by emmett442
Production trucks and busses are kept BOF because their platforms are multipurpose and need to be kept versatile/adaptable. NOT because of strength.
Hard to convert a unibody truck to a tow, tank, utility, box, flat, etc. Trucks and busses would be EXPONENTIALLY more expensive if they were produced unibody style and each had to be developed and produced individually.
Agree on versatility. That said, body on frames are strong, especially in torsional strength when compared to unibody vehicles. The frame takes most of the stress, when the body of a vehicle is forced into different orientations, often at the same time (fr off road use, towing, etc). A unibody will require a lot of engineering to deal with the stresses, which is why you dont see them offering the highest towing ratings (though there are some capable unibody off road vehicles from Jeep), though that management of stresses across the whole body is why they can do quite well on impact impact, granted with more extensive damage and in some cases long-term compromised integrity.