system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Its said that cars are "weaker" because they're now made from a softer material proper to receive impact, thus providing safety to the driver. How will safety work with cybertruck's 30x 'ultrahard' stainless steel when crashing?
gpt
Hard is not the same as tough is not the same as strong.

Cybertruck's stainless steel body panels are hard; they're probably also tough, although that's usually not very relevant for body panels. They're not any stronger than they need to be though (since that's what drives weight), so their crash behavior shouldn't be meaingingfully different.

Hard = how easy it is to scratch. This is obviously really relevant for vehicle body panels, we want them to stay looking nice, harder materials are harder to scratch and stay good looking for longer.

Tough = how easy it is for a crack to grow. Body panels don't usually crack so this isn't a big deal. It's a huge deal for fatigue-critical structure (stuff that goes through a lot of stress cycles) but that's also not usually a big deal for body panels, they're mostly decorative and not carrying nearly as much load as the chassis.

Strong = how much stress it can carry without yielding (permanent deformation). Cybertruck doesn't need to be 30x stronger...it might be 1 or 2x stronger because of the extra battery weight, but nowhere near 30x. That would just be wasted weight, which drives down range and drives up costs, so there's no reason to do that.