1998 Pontiac Grand Prix Owner's Manual - Page 322

After the tires have been rotated, adjust the front and rear inflation pressures as shown on Tire-Loading the Information label. Make certain that all wheel nuts are properly tightened.See "Wheel Nut Torque" in the Index. When It's Time forNew Tires One way to tell when it's time for new tires is to check the treadwear indicators, which will appear when your tires have only 1/16 inch (1.6mm) or less of tread remaining. L Rust or dirt a wheel, or on the partsto which on it is fastened, can makewheel nuts become loose after a time. The wheel could come off and cause an accident. When you change awheel, remove any rust or from places where thewheel dirt attaches to the vehicle. In an emergency, you can use a cloth or a paper towel to dothis; but be sure touse a scraper orwire brush later, if you need to, to get all the rust or dirt (See off. "Changing a Flat Tire" in the Index.) .. I YOUneed a new tire if any the following statements of are true: 0 0 I I 0 0 0 You can see the indicators at three or more places around the tire. You can see cord orfabric showing through the tire's rubber. The treador sidewall is cracked, cut or snagged deep enough to show cord fabric. or The tire has a bump, bulge or split. The tire has a puncture, cut or other damage that can't be repaired wellbecause of the size or location of the damage. 6-47