1998 GMC Suburban Owner's Manual - Page 337

When to Check NOTICE: Don't let anyone tellyou that underinflation or overinflation is all right. It's not. If your tires don't have enough air (underinflation you can 1, get thefollowing: Too much flexing 0 Too much heat 0 Tire overloading 0 Badwear 0 Badhandling 0 Bad fuel economy. If your tires have too much air (overinflation you can get the following: Unusualwear Badhandling 0 Roughride Needless damage from road hazards. Check your tires once a nlonth or more. Also, check the tire pressure of the spare tire. How to Check Use a good quality pocket-type gage to check tire pressure. You can't tell if your tires are properly inflated simply by looking at them. Radial tires may look properly inflated even when they're underinflated. Be sure to put the valve caps back on the valve stems. They help prevent leaks by keeping out dirt and moisture. Tire Inspection and Rotation Tires should be rotated every 6,000 to 8,000 miles (10 000 to 13 000 km). Any time you notice unusual wear, rotate your tires as soon as possible and check wheel alignment. Also check for damaged tires or wheels. See "When It's Time for New Tires" and "Wheel Replacement" later in this section for more information. 6-45