One of the simplest - & most important - things you can do to keep your tires in good shape is to make sure that they are properly inflated. You must check your tires’ air pressure regularly, because tires normally lose pressure over time. If one of your tires has lost two pounds per square inch (psi) or more of air pressure, look for signs of punctures, valve leakage or damage that may account for the air loss. Also, a rapid drop in temperature can cause your tires to lose pressure. Expect to lose one or two psi when the thermometer dips by 10° F. An under-inflated tire might not seem like a big problem, but it can have a big impact in terms of safety & reliability.

Driving on any tire that does not have the correct inflation pressure is dangerous - & under-inflation is the leading cause of tire failure. Underinflation can make it harder to steer & stop your vehicle, result in loss of vehicle control, cause sudden tire destruction, & lead to serious injury or death. As important as tire inflation is, however, many people seem to ignore it. According to the National Highway Traffic Safety Administration (NHTSA), about 25 percent of U.S. passenger cars-& about 33 percent of sport utility vehicles-have one or more substantially under-inflated tires.

Tires that have been run even short distances while severely under-inflated may be damaged beyond repair, & should be checked by a professional.

There is no universal "right" pressure for all tires. The proper inflation level will depend on what tires you have, & it may even be different for your front & back tires. To find the correct pressure for your tires, look at the tire information placard that’s mounted inside the frame of the driver’s door, in the glove box or inside the fuel door. You can also get that information in your vehicle owner’s manual & from your tire dealer.

It’s important to be accurate in filling your tires. Don’t try to "eyeball" the pressure - a tire can lose half its pressure without looking flat. Instead, use a reliable tire pressure gauge. It’s also a good idea to have your own gauge, because you can’t always count on the gauge on the air hose at the gas station.

According to the NHTSA, less than half the gas stations with air pumps provide a tire pressure gauge for customer use. Even if there is one, it may not be accurate-about 20 percent of the gauges on station pumps are damaged or off by four pounds or more.

According to the NHTSA, about one out of every 10 cars on the road has at least one worn out or bald tire. There are several things you can do to stay out of that group, & help the tread last longer on your tires. For starters, make sure that your tire dealer balances your tires when installing them. Balancing involves placing small weights on the rim to counteract heavy spots, or slight variations in weight, in the wheel. If a tire is not balanced, it will shimmy as you drive, & your tread will wear down quickly.

You must also make sure that your car’s suspension is properly aligned. Otherwise, your tires will ride at an angle & wear unevenly, & you may experience handling problems. A car can become misaligned gradually over time, or suddenly when you hit a bump or pothole.

Have a mechanic check your alignment periodically, as suggested in your owner’s manual. Also, have it checked if you notice anything unusual, such as pulling to one side or vibrating. This could be a sign of tire trouble, such as impending tread/belt separation.

There are various patterns for rotating tires. A common one for front-wheel drive vehicles involves moving the tires in a criss-cross fashion, with the left front tire trading places with the right rear, & right front trading with the left rear. If you have a full-size spare, you can include it in your rotation pattern-but don’t do so with a small "temporary use" spare, because those are meant only for low-speed, short-distance emergency use.