Checking the air pressure in your car's tires on a regular basis is important as tires that do not have enough pressure in them can result in increased wear, waste of gas and car accidents due to tire blow-outs. Tire pressure is measured in pounds per square inch (PSI).

A correct amount of tire pressure means that the tires are worn evenly and not too quickly.

The recommended PSI, usually given as a maximum, will depend on the tires you use. You can find this information on the side of the tires, as depicted in the image below.

If you are unsure what the recommended PSI for your tires is, consult the owner's manual for your car or ask a car mechanic for guidance.http://www.youtube.com/watch?v=VMUvZYVQHuY 

Tire pressure is measured by using air pressure gauges. You will also need a source of air if the tire pressure is low and you want to add more air to the tires. Most gas stations provide air for free or a small fee.

There are both basic analog and digital air pressure gauges. Basic air pressure gauges are read by looking at a metered stick.

Digital air pressures gauges are often easier to read and give more accurate results. Some digital air pressure gauges require the use of batteries.

It's best to check air pressure when you have not driven for a few hours. Since that is not always feasible, avoid driving more than a mile before checking tire pressure.

1. Locate the valve stem on your tire and unscrew the valve cap.
2. Press the tire gauge onto the valve stem to get a reading.
3. Read the tire pressure at the end of your analog gauge or on the screen of your digital gauge.
4. Repeat Steps 1-3 on the remaining three tires.
5. Add more air to the tires that need it making sure you do not exceed the maximum PSI.