1996 GMC Sonoma Owner's Manual - Page 267

Inflation - Tire Pressure The CertificationRire label which is on the driver's door door edge, above the door latch, shows the correct inflation pressures for your tires when they're cold. "Cold" means your vehicle has been sitting for at least three hours or driven no more than a mile. NOTICE: (Continued) If your tires have too much air (overinflation), you can get the following: Unusual wear 0 Bad handling 0 Rough ride 0 Needless damage from road hazards. When to Check Check your tires once a month or more. Also, check the tire pressure of the spare tire. If you have a compact spare tire, it should be at 60 psi (420 kPa). 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 backon the valve stems. They help prevent leaks keeping out dirt and moisture. by NOTICE: Don'.t.let anyone tell that underinflation or you overinflation is all right. It's not. If your tires don't have enough air (underinflation), can you get the .following: 0 Too much flexing 0 Too much heat 0 Tire overloading 0 Bad wear 0 Bad handling 0 Bad fuel economy. NOTICE: (Continued) . 6-45