Pontiac 2004 Grand Prix - Manual (Page 349)

Inflation -- Tire Pressure
The Tire-Loading Information label, which is on the
inside of the trunk lid, 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).
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:
• Too much flexing
• Too much heat
• Tire overloading
• Bad wear
• Bad handling
• Bad fuel economy
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.
Don’t forget your 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 prevent leaks by keeping out dirt and moisture.
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