See Figure 1
Tire wear can be equalized by switching the position of the tires about every 7,500 miles (12,000 km). Including a conventional spare tire in the rotation pattern can give up to 20% more tread life. Do not include a SpaceSaver® or other temporary spare tire in the rotation pattern.
See Figures 2, 3, 4 and 5
All tires made since 1968 have 8 built-in tread wear indicator bars that show up as 1 / 2 in. (13mm) wide smooth bands across the tire when 1 / 16 in. (1.6mm) of tread remains. The appearance of tread wear indicators means that the tires should be replaced. In fact, many states have laws prohibiting the use of tires with less than 1 / 16 in. (1.6mm) of tread remaining. Tread thickness under 1 / 16 in. (1.6mm) is very dangerous on wet roads due to hydroplaning.
You can check your own tread depth with an inexpensive gauge or by using a Lincoln head penny. Slip the Lincoln penny into several tread grooves. If you can see the top of Lincoln's head in 2 adjacent grooves, the tires have less than 1 / 16 in. (1.6mm) of tread left and should be replaced. You can measure snow tires in the same manner by using the tail side of the Lincoln penny. If you see the top of the Lincoln memorial, it's time to replace the snow tires.
Wear that occurs only on certain portions of the tire may indicate a particular problem which, when corrected or avoided, may significantly extend tire life. Wear that occurs only in the center of the tire indicates either overinflation or heavy acceleration on a drive wheel. Wear occurring at the outer edges of the tire, and not at the center may indicate underinflation, excessively hard cornering or a lack of rotation. Wear occurring at only the outer edge of the tire, may indicate a problem with wheel alignment or, perhaps, a non-uniformity defect in the tire.
When you replace tires, never mix radial, bias-belted or bias type tires. Use only the tire sizes listed on the tire decal attached to your vehicle on the driver's side door post. Make sure that all tires are the same size, speed rating and load carrying capacity. Use only tire and wheel combinations as recommended on the tire decal or by your dealer. Failure to follow these precautions can adversely affect the safety and handling of your vehicle.
See Figures 6 and 7
Store the tires at their recommended inflation pressures if they are mounted on wheels. All tires should be kept in a cool, dry place. If they are stored in the garage or basement, do not let them stand on a concrete floor; set them on strips of wood.
Tire inflation is the most ignored item of auto maintenance. Gasoline mileage can drop as much as 0.8% for every 1 pound per square inch (psi) of underinflation.
Two items should be a permanent fixture in every glove compartment: a tire pressure gauge and a tread depth gauge. Check the tire air pressure (including the spare) regularly with a pocket type gauge. Kicking the tires won't tell you a thing, and the gauge on the service station air hose is notoriously inaccurate. Also, just looking at the tire does not indicate if it is underinflated.
The tire pressures recommended for your car are usually found on a label attached to the door pillar, on the glove compartment's inner cover and in the owner's manual. Ideally, inflation pressure should be checked when the tires are cool. When the air becomes heated; it expands and the pressure increases. Every 10°F (-12°C) rise (or drop) in temperature means a difference of 1 psi (7 kPa), which also explains why the tire appears to lose air on a very cold night. When it is impossible to check the tires cold, allow for pressure build-up due to heat. If the hot pressure exceeds the cold pressure by more than 15 psi (103 kPa), reduce your speed. Otherwise internal heat is created in the tire. When the heat approaches the temperature at which the tire was cured during manufacture, the tread can separate from the body.
CARE OF WHEEL COVERS AND ALUMINUM WHEELS
To clean the wheels, wheel covers and wheel ornamentation, use a mild soap solution and thoroughly rinse with clean water. Do not use steel wool, abrasive type cleaner or strong detergents containing high alkaline or caustic agents, as damage to the protective coating and discoloration may result.