How to stretch the life of your tire tread

The amount of tread on a tire is critical in determining how well it will vacate water to maintain contact with the road in the rain, according to Consumer Reports. If your tires wear out quickly, your safety may be at risk.

Consumer Reports' research indicates that when people shop for tires, their primary considerations are price, availability and tread wear. Prices are easy to find. But until now, consumers had to rely on the government's tread-wear ratings or mileage warranty claims from manufacturers - if available - to judge how well tires would wear.

That's why Consumer Reports tests two tires per model over six months of driving 16,000 miles on public roads through the scrub grass of West Texas. In the past, CR's testers scored tread wear on a standard 5-point scale. Now CR lists projected mileage based on how tires wear in their tests.

Of course, there's more to a good tire than long life. But longevity is a key to whether a tire you're considering is a good deal. Noteworthy in the findings is that almost half of the 47 all-season and performance all-season tires could last at least 65,000 miles; a half dozen could top 85,000 miles or more. And there's a wallet-friendly surprise: Tires with the longest life don't necessarily cost the most.

Stretching tire life

Consumer Reports offers this advice on how to stretch the life of your tires:

• Keep the pressure up. Maintaining correct inflation pressure is important for maximizing tire life and keeping you safe. Check at least once per month - when tires are cold • and before long trips. Underinflation can affect handling and build excess heat within the tire, leading to failure. You can find the correct pressure on a label in the car, usually on the driver's doorjamb. But it's not the "max. pressure" found on the tire itself.

• Straighten out. Have alignment checked for all four wheels at the intervals spelled out in the owner's manual, after any serious pothole bump and when installing new tires. Improper alignment can shorten tire life.

• Rotate regularly. For even wear, tires should be rotated as specified in the owner's manual or new-tire warranty guidelines, usually every 5,000 to 8,000 miles.

• Skip the donuts. If you like to squeal your tires on takeoff and grind them on curves, what you're hearing is rubber getting left on the road. If you want your tires to last, take it easy, especially on bad roads, and try to avoid potholes and broken pavement.

• Don't go bald. Tread depth is measured from the top of the tread to the deepest groove. Tread-wear bars at the bottom of the groove appear flush with the tread when there's 1/16 inch remaining. That's when the tire is truly worn out in most places. But Consumer Reports recommends shopping well before then, when 1/8 inch remains. A quarter inserted upside-down in a tread groove can serve as a gauge. If the top of Washington's head is visible above the tread, it's time to shop for tires.

• Quick change. The extra slits and pliable rubber that make winter tires so exemplary at handling ice and snow are the same things that make them wear down more quickly on cleared roads. Be sure to remove winter tires as soon as the threat of inclement weather passes, so that you can get as many winters out of those tires as possible.