2003 Pontiac Grand Prix Owner's Manual - Page 295

Don't include the compact spare tire in your tire rotation. After the tires have been rotated, adjust the front and rear inflation pressures as shown on the Tire-Loading Information label. Make certain that all wheel nuts are properly tightened. See "Wheel Nut Torque" under Capacities and Snncifjcations on page 5- 102. When It Is Time for New 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 (1.6 mm) or less of tread remaining. Rust or dirt on a wheel, or on ,,le parts to which it is fastened, can make wheel nuts become loose after a time.The wheel could come off and cause an accident. When you change a wheel, remove any rust or dirt from places where the wheel attaches to the vehicle. In an emergency, you can use a cloth or a paper towel to do this; but be sure to use a scraper or wire brush later, if you need to, to get all the rust or dirt off. See "Changing a Flat Tire" in the Index. You need a new tire if any of the following statements are true: You can see the indicators at three or more places around the tire. You can see cord or fabric showing through the tire's rubber. 0 The tread or sidewall is cracked, cut or snagged deep enough to show cord or fabric. 5-70