How to Check Tire Pressure

When it comes to tire safety, tire pressure is perhaps one of the highest factors on the list. Monitoring your tire pressure on a regular basis can alert you to problems that might eventually cause a serious accident. I try to check every two weeks, and to keep myself honest I record the numbers in a little reporter's notebook that I keep with the tire gauge in the glove compartment.

That might sound a little obsessive, but it helps me keep track of gas mileage as well as the condition of my tires. Checking tire pressure also gives you a chance to inspect each tire for any excessive tread wear, nails, or scrapes.

Know the Players

To check tire pressure, all you need is a tire gauge, which you can purchase at an auto supply or big box store for under $10. If you find the tire is under-inflated, however, you will also need a source of compressed air, such as what you find at gas station.

It is important to know the recommended or maximum PSI (pounds per square inch) of pressure for your particular vehicle. This is found on the sidewall of the tire, often in raised letters, with the words "Recommended PSI" before the number.

If you want to be able to take care of all tire pressure issues at home, you can purchase a portable air compressor to keep in your garage. Some plug into the cigarette lighter in your vehicle, while others can be plugged into a wall outlet or run from batteries. This is only if you want to avoid using the gas-station compressor, where you will probably have to spend $0.50 to $0.75 for each usage.

Checking Tire Pressure

Remove the caps from the valve stems on each of your tires. Take your tire pressure gauge and press it firmly over each valve stem, holding for two or three seconds before removing it. Don't be alarmed if you hear the sound of escaping air during this process; it's normal.

Read the number given on the tire gauge and compare it to the number recommended on the tires. If it is lower, you will need to add air to your tires. If it is higher, it means the tire is over-inflated and you should let air out.

Keep in mind that checking tire pressure is only accurate when the tires are cool, according to Edmunds. If you need to check tire pressure after you've been driving, add 3 psi to whatever number the gauge gives you to compensate for the difference.

Adding Air

If your tire pressure indicates the tires are under-inflated, you will need to add air using the compressor, either at the gas station or at your home. This is simple. Just place the hose nozzle over the valve step and allow it to fill the tire with air. Continually check the tire pressure until you've reached the recommended psi level.