Tire Service Guide
You car’s tires affect its ride, handling, traction and safety. Tires are the critical connection between your car and the road in all sorts of driving conditions.
To maximize tire life and safety, check tire condition and inflation pressure regularly and have the tires rotated and balanced. Tire replacement may be necessary if the tread depth is below the minimum legal requirement, or the sidewalls are severely cracked or punctured. In some cases, tread punctures cannot be repaired.
Tire Service Checklist
- Check inflation pressure at least once a month (including the spare).
- Have the tires rotated every 6,000 miles.
- Rotation time also serves as a good opportunity to have the tires balanced.
- Uneven or accelerated tire wear may indicate an alignment problem. Have you car’s alignment checked at least once a year.
What is it?
Proper tire inflation pressure is the specified air pressure given by a carmaker for a certain tire on a specific vehicle. This pressure specification should not be confused with a tire’s maximum pressure, which is usually listed on the tire’s sidewall. Some vehicles may specify different pressures for the front tires and the rear tires.
Correct inflation pressure is critical for good fuel economy, safety, maximum tire life, and proper vehicle handling performance.
For the small amount of time it takes, checking tire inflation at least once a month is one of the best investments you can make to get the maximum life out of your tires. Proper inflation can also improve gas mileage by more than 3%, when maintained regularly. Keep this in mind: Under-inflated tires can lower gas mileage by 0.4 percent for every 1 psi (pounds per square inch) drop in pressure of all four tires. You may want to check your tires more often during the winter months. Tires will lose about 1 psi of pressure for every 10 degrees Fahrenheit of temperature drop.
Keep an accurate tire pressure gauge in your car’s glove box (many gauges at “air stations” give false pressure readings) and check the tire pressure when the tires are cold. Never trust the appearance of a tire as a gauge for inflation. A tire could be 10 psi low on pressure and not appear to be low on air. Use the recommended inflation pressure listed in your vehicle’s owner’s manual or on the inflation sticker found on the driver’s door jamb. While you’re at it, don’t forget to check the spare. There’s nothing more annoying than a flat spare when you have a flat tire.
What is it?
There are several simple ways to check tire tread depth. The first way is to measure tread depth with a tread depth gauge. The second method involves the use of a penny inserted into the grooves of the tread. Tire wear bars are also used on today’s tires as a hands-off visual indication that a tire needs replacement.
What does it do?
Regular tread depth checks are important to ensure that your car’s tires are safe. Excessive wear can result in a loss of traction, especially on wet and slippery roads. Tires are regular wear items and staying on top of their condition not only ensures your safety, but also gives you the opportunity to plan ahead and budget for inevitable tire replacement.
When using a tread depth gauge, tires need to have at least 1/16-in. of tread or more (this is the minimum amount of tread allowed by law). By using a penny as a quick reference, insert the penny into the tread groove with Lincoln’s face showing, but with his head upside-down. If you are able to see all of Lincoln’s head, the tire needs replacement. If you see a wear bar across the width of the tread while facing it, it’s time to replace the tire. Generally, it’s best to replace tires in sets of four. If your car’s tires show signs of abnormal or unequal wear, have this looked into by a professional technician. Excessive wear on both outer edges generally indicates under-inflation. Excessive wear in the center of the tread generally indicates over-inflation. Cupping or dipping of certain tread sections may indicate worn suspension parts or a wheel balance problem. Saw-toothed or feathered tread edges may indicate wheel misalignment. If your car needs alignment or suspension work, have it done before you drive off with a new set of tires. Taking a “big picture” approach to protecting your tire investment will reap many rewards for miles to come.
Unbalanced wheels can cause rapid wear of shock absorbers and struts, and wheel balance can change as a result of normal tire wear. On full-time four-wheel drive vehicles, a difference of only 1/4 inch between the outside circumference of the front and rear tires can cause expensive damage to the transfer case or center differential. Rotating the tires to keep their sizes equal is critical on these vehicles, and replacing all four tires at the same time, rather than just the front or rear tires, is highly recommended.