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 (usually given in PSI cold)
- Gross vehicle weight rating (GVWR)
- Gross axle weight ratings (GAWR) for front and rear axles
Both placards and certification labels are permanently attached to the vehicle door edge, door post, glove-box door, or inside of the trunk lid. You can also find the recommended tire pressure and load limit for your vehicle in the vehicle owner’s manual.
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.)
Manufacturers of passenger vehicles and light trucks determine this number based on he 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.”
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 curb when parking.
- With radial tires, it is usually not possible to determine under inflation by visual inspection.