Tires Can Wear Out Even If They Haven’t Gone Very Far
If you’re thinking about buying used tires for your vehicle, there are some important points to consider. When a tire is between six and 10 years old, its rubber and internal components will begin to get dry rot. (If there is dry rot, you’ll notice cracks in the treads, discoloration and that the tire is misshapen, says Car and Driver.) Tires can degrade and weaken even if they haven’t gone very far or done much. For example, a 9-year-old car may only have 10,000 miles on the odometer, but it might need new tires.
When a tire needs to be replaced depends on several factors, according to Edmunds, including how it is used (such as not being inflated properly), exposure to heat and how it was stored. Here are a few things to keep in mind if you’re considering buying used tires or are wondering if you should replace older tires:
It can be difficult to accurately determine age-related tire damage. That’s because the conditions in a climate-controlled warehouse help prevent a tire from deteriorating. However, one left in the sun on display may be almost worn out inside before it’s mounted on a vehicle. And, the ones I put in the cool crawl space under my house in garbage bags are somewhere in between. Still, some car makers recommend replacing tires that are between six and 10 years old, regardless of how much tread is left, says the National Highway Traffic Safety Administration (NHTSA).
Almost every driver can find out a tire’s age just by decoding numbers on the tire. Your tire’s “born-on date” is on its sidewall, part of the government-required Tire Identification Number (TIN), according to NHTSA. The TIN is an alphanumeric code that begins with “DOT” (the abbreviation for the Department of Transportation). The last four digits indicate the week and year in which the tire was made. A TIN ending in 0112 means the tire was made in the first week of 2012. (If the DOT code ends with a letter or contains less than 10 digits, check the opposite sidewall. If you can’t find such a number or it has been ground off, assume the tire is far too old for safe use.)
While there is no way to track the history of a used tire, it’s safe to assume it likely was driven without being inflated properly, as the NHTSA states that only 19 percent of people have inflated their vehicle’s tires properly. Also, a used tire could have suffered significant damage from a pothole, been repaired improperly or permanently damaged when being dismounted. Because these factors may affect a tire’s safety, Consumer Reports advises against buying used tires. But if you do, make sure to have the used tire properly inspected by a tire professional before purchase and installation.
If you’ve just acquired a used car and encounter otherwise untraceable issues with tire wear, handling, excessive noise or the like, check to make sure all four tires were produced at the same plant at about the same time. It’s ideal if the TINs are identical on all four tires and, if applicable, the spare.
Tire manufacturers often make changes during production runs and sometimes produce the same product in multiple plants. A tire made a couple of years after or in a different plant than its otherwise visually identical sibling may have subtle but important differences. Check the plant code, which is immediately after DOT on the TIN. You can use the plant code to find where your tire was built at the NHTSA’s Product Information Catalog and Vehicle Listing.
Remember to check your spare tire, too. (You may find you don’t have one!) It’s possible to have a spare that’s never touched the ground but is so old that it should not be used. And finally, to help ensure your tires are properly inflated, the NHTSA recommends that you check the pressure of all your tires (even the spare) monthly.
Originally published on September 22, 2014.