[danheskett]

No amount of engineering can change the basics of physics. A firetruck has a roll weight of in the ballpark of 50,000 lbs. A Tesla has the ballpark weight of 4,000 lbs.

You need a lot of V to make up for that difference in M.

On top of that, a firetruck is typically built on really tough commercial chassis which has a feature a lot of rigidity.

[linsomniac]

Somewhat related fascinating take: A schoolbus driver did a tiktok saying, roughtly: For its size, a schoolbus is a relatively lightweight vehicle. We don't have Mansfield Bars because we don't want to absorb the impact of you running into the back of us and pushing us into children. Instead, you go underneath and the children have a better chance of surviving. Pretty sobering.

[mcint]

It's worth separating the momentum M*V you're referring to, from the energy M*V^2 that's dissipated in deformation in the collision.

Hmm I'm not quite satisfied even by my clarification. Car and truck chassis strength needs to scale with something closer to M*V^2, so the truck chassis is multiple times stronger.