I found that very interesting, so I did a little research, and yeah, it’s called the “fourth power law”, which is used to compare road wear between two vehicles. The strength of the road does pretty drastically change how closely the “rule” applies, but it does seem to be a decent rule of thumb for common paved secondary roads. For anybody reading, it’s based on axle loading. So if we assume a 50/50 weight balance on a standard 2-axle vehicle, its axle loading is half the vehicle weight. The difference in road wear can be calculated as
([Greater Axle Load]/[Lesser Axle Load])^4^
So if you compare a Hummer EV at roughly 10,000lbs, so 5,000lb axle loading, to a 1st gen Miata at about 2,000lbs, or 1,000lb axle load, the Miata would have to drive down a road 625 times to do a similar amount of damage as the Hummer driving down it once. That is a fairly extreme example, but you get the idea.