[papajam]

I mean no disrespect BigSwede, but I think you might be confusing caster and camber. Caster is the non-tire wearing angle (unless the side to side differential is like 5 degrees or something) but camber most certainly is a tire wearing angle.
For street cars, excessive tire wear is caused, by far, by incorrect tire pressure (Alfa owners seem to be better than most at maintaining proper pressure though). Next is camber. Then toe; either in or out.