Maintaining Correct Tire Inflation Pressure

The benefits of maintaining correct tire inflation pressure are well known. Better gasoline mileage, longer tire wear, the car handles better, etc. What isn't so well known is what the correct tire inflation pressure should be for your car and how to find it.

Finding the correct tire inflation pressure
This information can be found on the tire information placard located on the edge of the driver's door, the driver's door post, on the glove box door, inside the trunk lid, or on the back of the gasoline filler door. If you can't find this information in any of these locations, it will be in your vehicle owner's manual.

Though tires have tire inflation pressures listed on their sidewall, this information will seldom be correct for your vehicle. The pressure listed on tire sidewalls is the maximum pressure the tire is designed for under maximum load conditions. For most vehicles, filling to the tire sidewall inflation pressure will ensure that your tires are over inflated, which can reduce tire life considerably.

Filling tires to the correct tire inflation pressure
When filling and checking your tires, be sure to use a good quality tire air pressure gauge. In fact, it is a good idea to carry an air pressure gauge in the vehicle. You may have noticed on the tire placard that the tire pressure is listed as PSI cold. Tires should be checked and filled when they are cold, before driving. The reason for this is because tires get warmer as they are driven on, and this increases tire pressure. Driving as little as one mile can warm tires up and change pressure readings.

The change in seasons will also change tire pressure due to the changing air temperature. For instance, assuming you had a tire that was known to not leak air, the pressure would still read lower with an air pressure gauge in winter due to the colder temperatures. The same tire would show a higher reading in summer because of – you guessed it – warmer temperatures. Air temperature changes, however, have no affect on how much pressure should be in the tire. Regardless of the temperature outside, you still fill your tires to the cold PSI that is listed for your vehicle.

Checking tire pressures at least once a month and maintaining the correct tire inflation pressure is something every car owner can do to increase safety and greatly extend the life of their tires.