The thing &#x27;size&#x27; gets you is crumple zones. A bigger vehicle has a lot more material that can be engineered to deform and absorb the energy of the impact, spreading the deceleration over a longer period of time.<p>A small car can be designed to prevent intrusion into the passenger compartment, but it can&#x27;t do anything about the g-forces of the collision (which can seriously ruin your day...).