1997 GMC Sonoma Owner's Manual - Page 283

Inflation -- Tire Pressure The Certificationrnire label,which is on the driver's door edge, above the door latch shows the correct inflation pressures for your tires when they're cold. "Cold" means your vehicle hasbeen sitting forat least three hours or driven no more than 1 mile (1.6 km). I NOTICE: (Continued) If your tires have too much air (overinflation), you can get thefollowing: 0 Unusual wear Bad handling 0 Roughride Needless damage from road hazards. When to Check Check your tires once a month or more. Also, check the tire pressure of the sparetire. NOTICE: Don't let anyone tell that underinflation or you overinflation is all right. It's not. your tires If don't have enough air (underinflation), can you get the following: Too much flexing 0 Too much heat 0 Tire overloading Bad wear Bad handling 0 Bad fuel economy. NOTICE: (Continued) 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 back on the valve stems. They help preventleaks by keeping out dirt and moisture. - 6-45