2008 Saturn Astra Owner's Manual - Page 243

Vehicle Service and Care 9-53 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. 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. • The tread or sidewall is cracked, cut, or snagged deep enough to show cord or fabric. • The tire has a bump, bulge, or split. • The tire has a puncture, cut, or other damage that cannot be repaired well because of the size or location of the damage. The rubber in tires degrades over time, even if they are not being used. This is also true for the spare tire, if the vehicle has one. Multiple conditions affect how fast this aging takes place, including temperatures, loading conditions, and inflation pressure maintenance. With proper care and maintenance tires typically wear out before they degrade due to age. If you are unsure about the need to replace the tires as they get older, consult the tire manufacturer for more information. One way to tell when it is time for new tires is to check the treadwear indicators, which will appear when the tires have only 1/16 inch (1.6 mm) or less of tread remaining.