1998 Pontiac Bonneville Owner's Manual - Page 293

NOTICE: Don't let anyonetell you that underinflation or overinflation is all right. It's not. If your tires don't have enough air (underinflation), you can get the following: 0 Too much flexing 0 Too much heat Tire overloading Bad wear Bad handling When to Check Check your tires once a month or more. Don't forget your compact sparetire. It should be at 60 psi (420 Wa). 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. Bad fuel economy. If your tires have too much air (overinflation), you can get the following: Unusual wear Bad handling 0 Rough ride 0 Needless damage from roadhazards. 0 6-42