[bandit86]

I know everyone here is happy to run their tires at the max number on the sidewall, and I guess for most vehicles it's not a problem as it is not significantly over the recommended pressure anyways.

I had a jeep wrangler with 31x10.5 bfgoodrich allterrain tires, the jeep called for 23 psi (stock tire size) and the tire could take 80psi max. obviously, that much air in a tire without a full load of weight pressing on it is going to ballon out, where your contac patch might be minimal. i had a chevrolet tracker with 33x12.5 mud tires on it, at 32 psi there was only 2 inches of contac in the middle of the tread. i drove over wet pavement and there was only 2 inches of wetness in the middle of the treads, so I know overpressuring tires has the opposite effect of low air pressure, where the middle of the treads will not ocntact the road and the tires wear out just on the outside.

I'm looking at a 2000 grand cherokee thats shoould remain stock, and my mom has a 2001 Gmc safari that already runs at 36psi all around. My safety is not worth saving 2 mpg, so how do you know if it's too much? is there a scientific way to tell because no two tires are ecer the same