1998 Oldsmobile Aurora Owner's Manual - Page 298

When It's Timefor New Tires Rust or dirt a wheel, or on the parts which on to it is fastened, canmake wheel nuts become loose after a time. The wheel could come and cause off an accident. When you change a wheel, remove any rust or dirt from places wherethe wheel attaches to the vehicle. In an emergency, youcan use a cloth a paper towel to do this; but be or sure to use ascraper or wire brush later, if you need to, to get the rust or dirt (See all off. "Changing aFlat Tire" in the Index.) One way to tell when it's time for new tires is to check thetreadwear indicators, which will appear when your tires have only 1/16 inch (1.6 mm) or less of tread remaining. 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. e The tread or sidewall is cracked, cut or snagged deep enough to show cord or fabric. e The tire has a bump, bulge or split. e The tire has a puncture, cut or other damage that can't be repaired well because of the size orlocation of the damage. 6-46