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I just bought a new-to-me motorcycle, and the tires look great. But are they? Having tread depth is only half the story with truck, SUV, and car tires, too, because even if a tire looks good, it could be old. Tires, like any other kind of rubber, degrade, and where I live in the desert the sun can cook the sticky stuff right out of them.

In my case, the new bike’s tires were made just a couple of years ago. How do I know that?

You can read a tire date code to learn when a tire was made to lean how old your tires are

Tires on a Ram truck showing the date code
The 4721 number on my truck tire mean this tire was made the 47th week of 2021 | Dan Mayfield, MotorBiscuit

The Department of Transportation mandates that all tires have a date code on the sidewall. Whether you’re looking at a new car, a used car, truck, or SUV, they all have four little numbers, usually inside an oval. Those four numbers are the date code and they tell you down to the week when a tire was made.

In the picture of my truck’s tires, for example, the code says 4721. That means the tires were made the 37th week of 2021. I bought the tires in December of 2021, so they were factory fresh when installed. That motorcycle? They have a code of 0122, so the tires don’t just look good they are good. Pirelli made them in the first week of 2022.

Tires are full of information beyond a tire date code

A man inspects a car tire
A man inspects a car tire for damage | Brian Brainerdvia Getty Images

Your tires are full of cool information beyond the date code and size. On the sidewall, you can find whether the tire is DOT certified (a must in the U.S.), where the tire was made, the size code, specifics about the tire and more. You can also learn where your tires were made, and you’ll quickly learn that most tires are made in China and Thailand.

The codes read like this: DOT designation, the plant code, the size code, specifics to the brand, then the week and year. With this information in hand, you might be able to haggle and get a better deal on a used car, or make sure that your new tires are, in fact, new.  You can find a complete list of codes HERE. You can also learn the speed rating, or fast the tire can safely go.

Buying used tires? Check the tire date code to lean how old your tires are.

Tires on a Honda CBR929rr showing the date code
This Pirelli tire on a Honda motorcycle shows it was made the first week of 2022. | Dan Mayfield, MotorBiscuit

Old or used tires can look fine, but they may have cracks, splits, or simply be too hard to drive on. Tire safety is super important and knowing how old a tire is can certainly help. One common rule of thumb when buying used tires (or a used car) is the six-year rule. Tires have a useful life of about six years, and anything older than that should be replaced. You may not even notice the degradation because tires degrade from the inside out, so the area where it attaches to the rim could be corroded and you might not know.

Many tires made before 1999 don’t have date codes. If you can’t find a date code, assume it’s too old to be useful anyway.

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