OH yea, it will hurt your car. Overtorqing the lugnuts will warp your rotors pretty darn fast. You use a torque-wrench to tighten those things. You can buy them just about anywhere for about 10-20 dollars. Good investment in the long run. Many uses too....like oil drain plug should be torqued at 33ft/lbs.

ANyways, does anyone know if im correct about the 80ft/lb theory?? Thanks.