Most drivers judge their tires by the tread. If there’s still plenty of rubber on the road, the tires must be fine, right? Not necessarily. Knowing how old is too old for tires is just as important a question as how much tread is left. Tires age whether or not they’re being used, and an old tire with deep tread can still be unsafe. The good news is that it only takes a minute to find out how old your tires really are. Here’s how to read the date code, spot dry rot, and know when it’s time to replace tires based on age alone.
Why Tires Have a Shelf Life
Tires are made of rubber compounds that slowly break down over time. Heat, sunlight, ozone, and everyday flexing all take a toll on the rubber, gradually drying it out and making it stiffer and more brittle. That aging process happens on the inside of the tire too, where you can’t see it, and it can weaken the bond between the tire’s internal layers. This is why a tire that looks perfectly fine from the outside can still be at higher risk of failure, especially at highway speeds or in hot weather when the tire is under more stress.
So How Old Is Too Old?
There’s no single federal law that sets a hard expiration date for tires, but the guidance from vehicle and tire manufacturers is fairly consistent. The general rule is to have tires inspected by a professional once they reach about six years old, and to replace them by around ten years from the date they were made, even if the tread still looks good. Some vehicle manufacturers are more conservative and recommend replacement closer to the six-year mark, so it’s worth checking your owner’s manual for your specific vehicle. Climate matters too. Tires that live in hot, sunny areas tend to age faster than tires in cooler, more moderate conditions.
How to Read the Tire Date Code
Every tire has a code stamped on the sidewall that tells you exactly when it was made. Here’s how to find it and read it:
- Look for the letters “DOT” on the sidewall, followed by a string of letters and numbers. This is the Tire Identification Number.
- Read the last four digits of that string. These digits are the date code, and they’re the only part you need to worry about.
- The first two digits are the week the tire was made, a number from 01 to 52.
- The last two digits are the year. For example, a code ending in 2419 means the tire was made during the 24th week of 2019, roughly mid-June.
- Check the inner sidewall if you don’t see it. On some tires, the full code only appears on the side facing the vehicle, so you may need to look at the opposite side or turn the steering wheel to get a better view.
- Don’t forget the spare. The spare tire has its own date code, and since it often sits unused for years, it can be surprisingly old.
If you ever see a tire with only a three-digit date code, it was made before 2000 and should not be in use under any circumstances.
A Quick Example
Say you check your tires today and find a code ending in 1618. That tire was made in the 16th week of 2018, which makes it about eight years old. It’s well past the point where a professional inspection is recommended, and it’s getting close to the outer limit most manufacturers suggest. A tire with a code ending in 3515, made in 2015, is already past the ten-year guideline and should be replaced regardless of how much tread it has left.
What Dry Rot Actually Is
Dry rot is the term most people use for the cracking and weathering that shows up in aging tire rubber. It’s not actual rot in the biological sense, but rather the rubber losing its natural oils and flexibility over time, especially when exposed to sun, heat, and ozone. Tires that sit for long periods without being driven are particularly prone to it, since regular rolling and flexing helps keep the rubber supple. Vehicles that are parked outside in direct sun, or that aren’t driven very often, tend to show dry rot sooner than daily drivers.
How to Spot Dry Rot and Other Warning Signs
A quick visual inspection is often all it takes to catch the early signs. Here’s what to look for on each tire:
- Fine surface cracks along the sidewall, which often look like tiny spiderweb lines or a pattern of small splits in the rubber.
- Cracks in the grooves between the tread blocks, which can be easy to miss unless you look closely at the bottom of the tread pattern.
- Faded or discolored sidewalls, where the rubber looks grayish or chalky instead of a deep, rich black.
- Bulges or bubbles on the sidewall, which can signal internal damage and are a serious red flag that calls for immediate attention.
- Stiff, hardened rubber that feels noticeably less flexible than it used to when you press on it.
- Vibration or ride changes that seem to have crept in gradually, which can sometimes point to internal aging or damage that isn’t visible from the outside.
Light, shallow surface cracking doesn’t always mean a tire is about to fail, but deeper cracks, cracks that reach down to the cords, or any bulging are good reasons to stop driving on that tire until it’s been looked at by a professional.
Why Good Tread Isn’t the Whole Story
It’s common for drivers with low-mileage vehicles, second cars, or trucks that sit most of the year to assume their tires are fine because the tread looks nearly new. But tread depth only tells you how much rubber is left on the surface, not how healthy that rubber is. A tire that’s eight or nine years old can still have plenty of tread and yet be far more likely to suffer a tread separation or blowout than a younger tire, especially under heavy loads, on long highway trips, or in hot weather.
What to Do If Your Tires Are Getting Old
If your tires are approaching the six-year mark, have them checked by a professional at least once a year from that point on. A technician can assess sidewall condition, look for internal damage you might miss, and tell you honestly whether the tires still have life left. If they’re ten years old or more, or showing deeper cracking or bulging, it’s best to replace them rather than trying to squeeze out another season. When you do replace tires, it’s also a good time to have your wheel alignment checked, and to have your suspension looked at if the old tires were wearing unevenly, since worn suspension components can shorten the life of a new set.
Make It Part of Your Routine
Checking your tire date codes takes about a minute per tire, and it’s one of the simplest things you can add to your regular preventative car maintenance routine. A good habit is to glance at the date code and sidewall condition whenever you check your tire pressure, so you’re never surprised by an aging tire that’s quietly getting riskier with time.
Not sure how old your tires are, or noticed cracks along the sidewalls? Contact us today to schedule a tire inspection. We’ll check the date codes and look for age-related wear so you can make an informed decision about whether it’s time for a replacement.