When you look at your tire wear bars, be sure to look at the entire surface of the wheel and not just one isolated location.
If you have a Canadian nickel, insert it between the tread with Queen Elizabeth’s crown facing down. If the top of her crown is visible, the tire is below 2⁄32 inch (0. 16 cm) and needs to be replaced. Tires do not wear evenly, so be sure to insert the coin at several points from the outside to the inside of your tires. Tires generally wear more on the inside, but over-inflated tires will wear more in the middle. For a more accurate tread depth measurement, use a tread depth gauge.
Repeat this process for the outer and inner circumferential grooves, and then average those numbers as well. To average numbers, divide the total by the number of individual measurements you made along the tread. Before using the tread depth indicator, push the tread depth gauge against a flat, hard surface and be sure it hits zero when it fully compresses. Don’t place the tread gauge onto any of the raised surfaces or molded tread wear indicators.
Call or email your country’s department of transportation or visit their website to locate tread laws. In some U. S. states, tires are considered to be legally worn out when they have decreased to 1⁄16 inch (0. 16 cm) of their remaining tread depth. In the U. K. , the minimum depth for tire tread is 0. 0456 inches (1. 16 mm) across the central 3/4 of the tread around the whole tire.
If uneven tire wear is extreme or if tires wear out much faster than expected, have a competent tire workshop check your suspension and correct it as necessary before replacing tires. Improper alignment or worn suspension parts can dramatically shorten a tire’s life. Rotate your tires from front to rear in pairs to avoid irregular tread wear. Take both front tires and move them to the rear and vice versa.
Such damage could be caused by driving through a large pothole, driving over a curb, or by driving with low tire pressure. Never continue to drive on a tire that has a sidewall bulge. This indicates that the structural integrity of the tire has been significantly reduced, which greatly increases the likelihood of a sudden failure or blowout at highway speeds.
If you experience vibrations in the absence of tread damage, try balancing and aligning your tires’ shock absorbers. If you notice tire vibrations along with other tire damage indicators like abnormal bulges and irregular tread wear, you probably have to replace your tire. If you notice that your tires are cupped—meaning they have a cupped or scalloped appearance around the tire—they likely aren’t being rotated enough.
Inspect for dry rot before heading out on any longer trips and bring your car in for a check-up regularly. Degrease your tires to prevent dry rot, especially if your tires are exposed to a high degree of sunlight.
If you’re having trouble finding the number, look for the initials DOT, followed by other letters and numbers. The code should appear following dot and will not contain any letters. Remember that although 10 years is the maximum service life for tires—which means since the date they were manufactured—this should never be used as the maximum drive time. Always err on the side of caution if you suspect your vehicle has tires that are over 6 years of age. Always change your tires if the tread is below the minimum depth recommendation, which is often 2⁄32 inch (0. 16 cm).
