2009 Chevrolet Cobalt Owner's Manual - Page 329

If the vehicle has the Tire Pressure Monitor System (TPMS), reset the TPMS sensors after rotating the tires. See Tire Pressure Monitor Operation on page 5-65. Make certain that all wheel nuts are properly tightened. See "Wheel Nut Torque" under Capacities and Specifications on page 5-124. When It Is Time for New Tires Various factors, such as maintenance, temperatures, driving speeds, vehicle loading, and road conditions influence when you need new tires. One way to tell when it is 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. { CAUTION: Rust or dirt on a wheel, or on the parts to which it is fastened, can make wheel nuts become loose after 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 needed, to get all the rust or dirt off. See Changing a Flat Tire on page 5-88. You need new tires 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. 5-71