Penny test simple, accurate way to check for tire wear

Proper tire maintenance is a vitally important safety function. The importance of properly maintaining your tires cannot be overemphasized. Remember, tires are the only contact between your vehicle and the road.

Got a Lincoln penny? If you do, you've got the perfect tire gauge. The "penny trick" works because the distance between the rim and Lincoln's head is 1/16 of an inch -- the minimum required tread depth. When your tire tread is lower than 1/16 of an inch, your vehicle can develop handling problems.

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Because a simple Lincoln head penny is the perfect size, using one will make it easy to determine when to buy new tires. And it only takes a few steps to check your tire depth:

• Pinch a Lincoln-head penny, from the base between your thumb and forefinger, so that the top of Lincoln's head is showing.

• Place the top of Lincoln's head into one of the tire tread grooves -- try to measure in the lowest point within the tread.

• If any part of Lincoln's head is obscured by the tread, you're all set -- you have a safe amount of tread. However, if you can see above Lincoln's head, then you are ready for a new tire.

You should always check your tires in several tread locations. Be sure to check the inner, outer and middle grooves of each tire, because tires can wear differently on each side, due to improper wheel alignment and/or low inflation.

Under inflation is the leading cause of tire failure. Improper tire-inflation pressure can cause severe internal tire damage, which can lead to sudden tire failure. A tire can be as much as 50 percent under-inflated before it is visibly noticeable. Not only are under-inflated tires more prone to damage and failure, but they can lead to higher fuel costs by as much as 3 to 5 cents per gallon.

Pressures should always be checked when the tires are cold on a monthly basis. Under normal tire operation, approximately 1 psi of tire pressure will escape every month. Also, for every 10 degrees F change in ambient temperature, tire pressure will change by approximately 1 psi. Check your owner's manual for the correct tire pressure recommended by the car manufacturer.

While checking tire-tread depth and tire pressure are both critical techniques to insure tire safety and performance, you should also rotate your tires every 5,000 -- 7,000 miles and perform visual inspections of tires for wear or damage every time you fill up at the pump.

Visit www.goodyeartires.com for more information on tire safety.