If a tire still has tread life left, does its age matter? The simple answer is yes, it does. While plays a big part in determining the life left in a tire, it’s not the only factor.
We’ve assembled this quick guide as a reference to the causes of tire aging, how to know your tire’s exact age and other factors to consider to keep you and your passengers safe on the road.
Causes of Tire Aging
A tire begins to age the moment after its manufacture. Over time, the natural rubber compounds in tires begin to oxidize. This causes the tire to become hard and brittle. When tires reach this point, they may have cracks, blisters, tears, or exposed cable piles in the sidewalls. If you see these, the tire is no longer safe to drive on as they have a much higher risk of puncture from road hazards or blow-out as a result of heating.
Heat produced by driving speeds the breakdown of the rubber compounds in tires. As the tire heats up, the rubber compounds get activated and bind together. Warm climates like those of Florida, Arizona, and Texas, as well as , increase the speed at which the rubber compounds break down.
Under-inflation and over-inflation will also wear a tire quickly. Misalignment damages tires too, and so does high mileage.
Of course, this begs the question: why do manufacturers give 60,000 or 100,000-mile warranties on their tires?
Simply put, these warranties are designed to protect you, the consumer. Look at the mileage warranty as how long you’re protected instead of an anticipated life of the tire. This benefits you if you do a lot of driving, or if your tires wear out sooner than anticipated.
Here’s how to know and track your tires age…
The manufacture date is printed on the sidewall of every tire. Since the year 2000, the tire includes the week and year it was produced in the tire identification number. The last four-digits tell you the week and the year it was manufactured (Learn more about the tire date code here).
Prior to the 2000, only three numbers were used. The first two to indicate the week; the final one indicated the year in the current decade it was manufactured.
Check Tread Depth
Advances in tire manufacturing has made it possible for tire treads to last longer. This provides consumers with a better value for their tire investment, but also means cars that drive low mileage will likely have tread left when it’s time to replace them.
Tires are considered no longer safe to drive when they reach 2/32” tread depth. Most auto-shops will recommend replacement at 4/32” or at least let you know you’ll need to replace them soon. You can check the amount of tread left for yourself as well; here’s several ways to check tread depth:
- Use a tread wear gauge. These can be purchased at many auto parts stores.
- The popular .
- A quarter works too. Insert a quarter, the same as you did the penny. If the tread reaches Washington’s head, you’ve got at least 4/32” left.
- Check the tread wear indicators. All tires come with tread wear indicators around the 2/32” mark from the bottom of the groove. You’ll know it when you see it, and if you do, it’s time to replace the tires.
Look at Wear on the Tires
Factors that can cause pre-mature wear in a tire include under-inflation, over-inflation, and misalignment.
- If a tire’s under-inflated, it will show excessive tread wear on the outer edges of the tire.
- If a tire’s over-inflated, the center tread will show much more wear than the sides.
- Misalignment causes a saw-tooth look on the tire as well as possible inside or outside wear.