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Finding Your Vehicle's Recommended Tire Pressure and Load Limits
Tire information placards and vehicle certification labels contain information on tires and load limits.
These labels indicate the vehicle manufacturer's information including:
Recommended tire size
Recommended tire inflation pressure
Vehicle capacity weight (VCW—the maximum occupant and cargo weight a vehicle is de signed
to carry)
Front and rear gross axle weight ratings (GAWR—the maximum weight the axle systems are
designed to carry)
Understanding Tire Pressure and Load Limits
Tire inflation pressure is the level of air in the tire that provides it with load-carrying capacity and affects
the overall performance of the vehicle. The tire inflation pressure is a number that indicates the amount
of air pressure—measured in pounds per square inch (psi)—a tire requires to be properly inflated. (You
will also find this number on the vehicle information placard expressed in kilopascals (kPa), which is the
metric measure used internationally).
Vehicle manufacturers determine this number based on the vehicle's design load limit, that is, the
greatest amount of weight a vehicle can safely carry and the vehicle's tire size. The proper tire pressure
for your vehicle is referred to as the "recommended cold inflation pressure." Because tires are designed
to be used on more than one type of vehicle, tire manufacturers list the "maximum permissible inflation
pressure" on the tire sidewall. This number is the greatest amount of air pressure that should ever be
put in the tire under normal driving conditions.
Checking Tire Pressure
It is important to check your vehicle's tire pressure at least once a month for the following reasons:
Most tires may naturally lose air over time
Tires can lose air suddenly if you drive over a pothole or other object or if you strike the
when parking
With radial tires, it is usually not possible to determine under-inflation by visual inspection
For convenience, purchase a tire pressure gauge to keep in your vehicle. Gauges can be purchased at
tire dealerships, auto supply stores, and other retail outlets.
The recommended tire inflation pressure that vehicle manufacturers provide reflects the proper psi
when a tire is cold. The term cold does not relate to the outside temperature. Rather, a cold tire is one
that has not been driven on for at least three hours. When you drive, your tires get warmer, causing the
air pressure within them to increase. Therefore, to get an accurate tire pressure reading, you must
measure tire pressure when the tires are cold or compensate for the extra pressure in warm tires.
ROUTINE MAINTENANCE
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