I like to give my car as much positive caster as I can as it handles better like that. And caster has nothing to do with tire wear. But to much makes the wheel harder to turn on manual steering. I believe stock specs for chamber are 0 to .5 but I would have to look up the specs to be sure. Camber can cause tire wear if to far out of specs. But I have not seen a car with camber set to factory specs where you could actually see the tire out to much at the top. Ron