Check Pressure Monthly
A passenger tire initially inflated to 35 (pounds per square inch (psi) can lose 1 psi each month. Properly check all four tires once a month and before a long trip.
Whether you have a full-size or mini spare, make sure that it is properly inflated as well.
Finding the Recommended Pressure
If you don’t know the proper inflation air pressure for your tires, check the following places:
- In the vehicle owners manual.
- On the vehicle's door jamb. (Often, a vehicle information placard is on the door jamb along with the recommended tire inflation pressure.)
- Inside the fuel hatch filler flap, in some vehicles.
- On the glove compartment door, in some vehicles.
But don't check the tire. The inflation pressure shown on the tire sidewall is the maximum tire inflation pressure. Usually, the vehicle manufacturer's recommended tire inflation pressure is on the vehicle placard. On some older vehicles, the vehicle manufacturer's recommended pressure may be shown as two numbers: one for city speed driving and normal load, and one for highway speeds and/or maximum capacity vehicle load. Be sure to inflate your tires to the recommended inflation pressure for each type of driving situation.
How to Properly Check Tire Pressure
- Beware of public pressure gauges at gas stations. They're often abused and unreliable.
- Buy a good pressure gauge and check it for accuracy with your tire retailer.
- Because air expands when it’s hot and contracts when it’s cold, it's best to inflate your tires in the morning before the day’s heat. Check your tires "cold" — before you’ve driven even one mile or at least three hours after the vehicle has been stopped.
Valves and Valve Caps
When it comes to proper tire pressure, the tire’s valve is a very important maintenance item. Valves are ordinarily made of rubber, so they can deteriorate over time. Replace them when you buy new tires. At high speeds, a cracked, deteriorated rubber valve stem can bend from centrifugal force and allow air loss.
The valve cap is also important. Buy high-quality valve caps that can help contain the tire’s air, should the core of the valve fail for any reason. Valve caps keep out moisture, which could freeze and in turn depress the valve core, causing air loss. The caps also keep out dust and dirt, which could interfere with the proper operation of the valve core and cause air loss.
Thanks to Michelin North America for providing information for this article. For more information on tire care go to MichelinMan.com
