Driving on any tire that does not have the correct inflation pressure is dangerous. Recent research by the National Highway Traffic Safety Administration (NHTSA) indicates about 30% of cars and light trucks have at least one tire under-inflated by 8 psi or more (DOT HS 809 317). Under-inflated tires and overloaded vehicles are the leading cause of tire failure. It is extremely difficult to tell just by looking at your tires if they are properly inflated.
Purchase an accurate tire gauge and check your tire pressures at least once a month along with their overall condition. Proper inflation pressure for your tires may be found in the vehicle owner's manual or the vehicle's tire information placard. If you have changed your tire size, ask the tire dealer for the new recommended inflation pressure. Never exceed the maximum pressure indicated on the tire sidewall.
Making sure that your vehicle is operating with properly inflated tires will make you safer on the highways and increase fuel savings.
Where To Find The Correct OE Inflation Pressure
You will find the original equipment (OE) recommended pressure on a placard or sticker in the door jam, glove compartment or near the gas cap. If your vehicle does not have a placard, check the owner's manual or consult the vehicle manufacturer, tire manufacturer, or your local tire dealer. The tire placard tells you the maximum vehicle load, the cold tire pressure, and the tire size recommended by the vehicle manufacturer. Air pressures may be different for front and rear tires. If your vehicle no longer is equipped with the OE size tires, consult your Toyo dealer for proper inflation information.
When To Check Tire Pressure
Check inflation pressure, including the spare, at least once a month and before every long road trip. Tires must be checked when they are cold which means you have driven less than one mile on them. If you must drive over a mile for air, measure and record the under-inflation amount of each tire. Upon arriving at the service station, measure each tire's inflation again and if the pressure has increased, adjust the amount of additional air pressure needed. For example, if cold pressure should be 35 PSI, but cold pressure was 28 PSI, and current pressure is 33 PSI, you should inflate the warm tires to 40 PSI and recheck them again when cold.
How Do Tires Lose Pressure?
Tires lose pressure naturally through the process of permeation or, air passing through the pores of the tire. Changes in outdoor temperature can affect the rate at which tires lose air. This change is more pronounced in hot weather. Generally speaking, a tire will lose one or two pounds of air pressure per month in cool weather and even more in hot weather. Remember, underinflation is the leading cause of tire failure, so check inflation pressure regularly.
- Never "bleed" or reduce air pressure when tires are hot. It is normal for pressures to build up as a result of driving.
- Make sure all tire valves and extensions are equipped with valve caps with rubber gaskets to keep out dirt and moisture. Have a new valve stem assembly installed whenever a tire is replaced.
Using Your Spare
Most vehicles come equipped with a temporary spare. These tires are usually much smaller than the other tires on your car. It is important to realize that these spares have far more limitations than a typical tire, including speed and recommended driving distance. Some spare tires even require the use of a special canister to inflate the tire.
You should familiarize yourself with the spare by reading the owner's manual and the sidewall of the spare. And remember to check the air pressure of your spare frequently.