The decision between replacing a car tire or repairing it is seldom straightforward. Fortunately, the low cost of good-quality used tires is making the decision easier these days. Use these guidelines to help you decide whether to repair a car tire or replace it.
Determine the Location and Extent of Damage
Usually, the first indication of tire damage is loss of air pressure - from an annoying slow leak to a dangerous blowout. Check the treads, the sidewall and the tire bead under the edge of the rim. You will need to determine why the tire deflated in the first place. Take the tire off the wheel, and examine the wheel, too, for any faults that may have punctured the tire from the inside.
A puncture, cut or split less than 1/4 inch in length in the tread may be repaired using various methods including patches and plugs. However, check the usable tread depth remaining before starting a repair. Tires with less than 1/16 inch of viable tread depth should not be repaired.
Tire Tread Repair
For a small puncture of up to 1/4 inch in diameter, a plug often works better than a patch. Patches are most suitable for cuts, splits or abrasions, called curb rash on the tire.
Non-Repairable Damage - Time for a Replacement
A split or cracked sidewall in a tire can never be safely repaired. Swap it for your spare tire at once, and replace it as soon as possible. Repair or replacement of a tire with tread damage will depend on the size and nature of the puncture, split or cut. Split and cracked beads, which must retain the majority of the tire's air pressure, are not repairable. Switch a tire with a damaged bead with a spare tire immediately, and get it replaced quickly if you are using a smaller-sized temporary spare. A problem with the wheel may be the cause of your tire damage. Check the condition of the wheel upon removing the damaged tire, and repair it, or replace it if it is badly bent, rusted or corroded.
Your vehicle's new tires came with a warranty separate from the one that covers the vehicle's drive train and other components. When the tire warranty expires, you do not need to replace your tires. Just maintain them by checking the tread monthly for stones, glass, nails and other items that can damage the tread or render it less effective at gripping the road. If one tire is damaged beyond repair, note the size of the tire embossed onto the sidewall, and purchase either a new or used tire of exactly those measurements. While used tires are not the ideal, they are cost-effective, in good condition and are much better than driving on a bulging, split or severely worn tire. Even if your tires are holding their air pressure well, continue to check the treads. Once blank bands about 1/2 inch wide, called tread indicators appear on the tread, the tire is no longer safe, and must be replaced. Replace your tires in pairs, for safer driving.