1998 Buick Skylark Owner's Manual - Page 263

When toCheck NOTICE: Don't let anyone you that underinflationor tell overinflation is all right.It's not. If your tires don't have enoughair (underinflation), you can get the following: 0 Too much flexing Too much heat 0 Tire overloading 0 Bad wear Bad handling Bad fuel economy. If your tires have too much (overinflation), air you can get the following: 0 Unusual wear 0 Bad handling 0 Rough ride 0 Needless damage from road hazards. Check your tires once a month or more. It Don't forget your compact spare tire.should be at 60 psi (420 Ha). How to Check Use a good quality pocket-type gage to check tire pressure. You can't tell if your tires are properly inflated look simply by looking at them. Radial tires may properly inflated even when they're underinflated. Be sure to put the valve caps back on the valve stems. They help prevent leaks bv keeping out dirt and moisture.