TLC for your tires

TODAY'S tires are designed better than ever before for peak traction, handling, and durability. But they need proper care for top performance and safety. Underinflation Up to 90 percent of all tires on the road are underinflated, and often hazardous. Underinflated tires reduce tread life and cause increased sidewall flexing, which can result in a blowout. And gas mileage can drop nearly 1 percent for every 1 pound per square inch of underinflation. Read your tires

Tires tell their own tale, of course. Excessive wear on both shoulders indicates underinflation. Wear in the center spells overinflation. Cupping or bald spots mean tires are out of balance or wheel bearings may be worn.

How your car handles provides additional clues. Does it vibrate at high speed, and does the steering wheel shake? Do you hear tire squeals when turning at normal speeds? Does your car pull to one side while cruising? These problems signal improper inflation pressures and/or wheel balancing and alignment problems. Inflation tips Check tire pressure, including the spare, every week or two - and always before a long trip. Tire pressures recommended for your car can usually be found on the glove-compartment door, on the door post, or in the owner's manual. Never judge inflation by ``eyeballing'' tires. Rely on an accurate air-pressure gauge, which you can buy at a tire or auto-parts store for a few dollars. Remember that radial tires have a normal sidewall bulge that makes them appear underinflated compared with other tires. Check inflation only when tires are cool. Pressures can increase six pounds or more when tires are hot from driving. Never bleed air from a hot tire. Before starting on a long trip with a trunk full of luggage, add 2 to 4 pounds of air to the tires to make them run cooler. Do not exceed the maximum inflation pressure listed on the tire sidewall. Potential hazards Check the tire treads for bits of glass, nails, and stones. Replace any tire if the tread depth is 2/32nds of an inch or less. Most modern tires have built-in tread-wear indicators. Examine the sidewalls for cracks, cuts, bumps, and unusual bulges. Inspect tire valves for cuts and leaks. Valves should be capped to keep out dirt and moisture. Mixing and rotating

Tires should be rotated every 6,000 to 8,000 miles, or at the intervals recommended in your car owner's manual. With bias and bias-belted tires, you crisscross tires from front to rear, and vice versa. Radials should be rotated front to rear on the same side of the car. Never include spare tires in the rotation, and mark tires when you remove them to preserve the direction of rotation.

Whenever you replace tires, remember that both tires on the same axle should be identical or a closely matched pair. Radials shouldn't be mixed with other tires. Other dos and don'ts

Have your car's alignment checked twice a year, in the spring and fall. Store tires in a cool, dry place; stand them on strips of wood, not concrete. Never wash tires with petroleum-based solvents, such as gasoline or kerosene. These can damage rubber by dissolving materials made to keep tires from cracking under direct exposure to sun and natural elements such as road salt and ozone. Use commercial tire cleaners with built-in rubber protectants.