Tires are of vital importance since they are the only part of the vehicle that makes contact with the road. Yet motorists often neglect their condition and age, and the results can be catastrophic. In its most recently available information, the National Highway Traffic Safety Administration says that 738 people died in 2017 from tire-related crashes.
As a tire ages, small cracks in the rubber begin to develop over time, appearing on the surface and inside the tire. This cracking can eventually cause the steel belts in the tread to separate from the rest of the tire. Tread separation can also happen to defective, underinflated and poorly maintained tires. Hot climates will also accelerate the aging process.
Here’s what you need to know to determine tire age and what issues old tires can pose:
How long do tires last?
Carmakers and tire manufacturers differ in their recommendations on when to replace a tire. Many automakers, including Ford, Nissan, Mazda and Mercedes-Benz, tell owners to replace tires six years after their production date regardless of tread life. Brands such as Continental and Michelin say a tire can last up to 10 years, provided you get annual tire inspections after the fifth year.
The NHTSA has no specific guidelines on tire age and defers to the recommendations of carmakers and tire manufacturers.
Determining the age of a tire
You’ll need to locate the U.S. Department of Transportation number printed on the sidewall of the tire. Tires made after 2000 will end in a four-digit code. The first two numbers represent the week in which the tire was made. The second two represent the year. A tire with a DOT code of 1018, for example, was made in the 10th week of 2018.
Tires made before 2000 end in a three-digit code that is trickier to decode, but essentially if you see a DOT number ending in three digits, the tire was made in the last century and should be immediately replaced.
If you see a partial DOT number on the outer sidewall, look for the full number on the inner side. Some tire manufacturers opt to brand the number on the inside to reduce the chance of injury to the tire mold technician.
Avoid used tires
New tires can be expensive, which is why used tires are attractive to people who are strapped for cash. You’ll often find used tires for sale in classified ads or at tire-and-wheel shops that offer them as a low-cost alternative.
The problem with used tires is that, while you can check their age, you have no idea how well they were maintained or what conditions they were used in. It is safer to avoid them entirely.
Get fresh tires
There are instances when people have purchased what they thought were new tires at retail stores only to find out that they were manufactured years earlier. A tire from the prior year is common, but anything older is likely to have a shorter life span. You have the right to request newer ones. Check the date before you drive away to save yourself the hassle.
Make a tire inspection part of your routine when evaluating a used car to buy. If you find that the vehicle you’re interested in has old tires, make that a part of the negotiation. The seller of the vehicle might be willing to discount the price so that you can buy new tires, or even install new tires before you purchase it.
Learn to let go of old tires
If your tires have plenty of tread left but are approaching the six-year mark, it’s time to get them inspected for signs of aging. And if the tire shop recommends a set of tires, spend the money and don’t put it off.
Getting rid of an unused spare or tires with plenty of tread may seem counterintuitive, but if they are too old, it is the smartest thing you can do.
