2004 Pontiac Montana Owner's Manual - Page 410

Inflation - Tire Pressure The Certification/Tire label or Tire and Loading Information label 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 1 mile (1.6 km). See Loading Your Vehicle on page 4-33. Notice: Don't let anyone tell 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: If your tires have too much air (overinflation), you can get the following: Unusual wear Bad handling Rough ride Needless damage from road hazards When to Check Check your tires once a month or more. Also, check the tire pressure of the compact spare tire. It should be at 60 psi (420 kPa). Too much flexing Too much heat Tire overloading Bad wear Bad handling Bad fuel economy 5-68