Tires need the correct amount of air pressure to operate effectively.
Notice: Do not let anyone tell you
that under-inflation or over-inflation is all right. It is not. If your
tires do not have enough air (under-inflation), you can get the following:
• Too much flexing • Too much heat • Tire overloading • Premature or irregular wear • Poor handling • Reduced fuel economy • Unusual wear • Poor handling • Rough ride • Needless damage from road hazards
A Tire and Loading Information label is attached to the vehicle's center pillar. This label lists your vehicle's original equipment tires and shows the correct inflation pressures for your tires when they are cold. The recommended cold tire inflation pressure, shown on the label, is the minimum amount of air pressure needed to support your vehicle's maximum load carrying capacity.
For additional information regarding how much weight your vehicle can carry, and an example of the Tire and Loading Information label, see Loading the Vehicle . How you load your vehicle affects the vehicle handling and ride comfort, never load your vehicle with more weight than it was designed to carry.
When to Check
Check your tires once a month or more. Do not forget to check the spare tire. If your vehicle has a compact spare tire, it should be at 60 psi (420 kPa). For additional information see Spare Tire .
How to Check
Use a good quality pocket-type gage to check tire pressure. You cannot tell if your tires are properly inflated simply by looking at them. Radial tires may look properly inflated even when they are under-inflated. Check the tire's inflation pressure when the tires are cold. Cold means your vehicle has been sitting for at least three hours or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem. Press the tire gage firmly onto the valve to get a pressure measurement. If the cold tire inflation pressure matches the recommended pressure on the Tire and Loading Information label, no further adjustment is necessary. If the inflation pressure is low, add air until you reach the recommended amount.
If you overfill the tire, release air by pushing on the metal stem in the center of the tire valve. Re-check the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve stems. They help prevent leaks by keeping out dirt and moisture.
Professional Vehicle
The proper inflation of the tires on your professional vehicle depends on the type of tires on it.
| • | If your vehicle has P235/60R17 size tires, the cold inflation pressure is 41 psi (284 kPa). |
| • | If your vehicle has LT235/60R17E size tires, the cold inflation pressure depends on the vehicle mass and should be determined by the vehicle coach-builder. A Tire and Loading Information label provided by the final stage manufacturer should be attached to the B-pillar on the driver's side of the vehicle. If the final stage manufacturer's label is not present, the coach-builder should be consulted. Do not use the tire pressures indicated on the General Motors label. These tire pressures are for the incomplete vehicle and are not the correct tire pressures for the completed professional vehicle. |
Operation at inflation pressures below this recommendation may cause your tires to become overloaded.
