Tire Date Code: Decode the DOT Week and Year
John Pearley Huffman draws on years of experience exploring cars and the decisions vehicle owners face. His knowledge covers how vehicles work, what makes them different, and practical considerations for understanding everyday automotive questions.
Quick answer
The last four digits of the DOT number on your tire sidewall show the week and year the tire was made. For example, 1319 means the tire was made in the 13th week of 2019. Tires made before 2000 use only three digits, which makes the exact decade impossible to confirm from the code alone.
What the DOT Date Code Actually Tells You
Every tire sold in the United States carries a Tire Identification Number (TIN), which starts with the letters DOT and can be up to twelve characters long. The date code is always the last four digits of that number. Those four digits are not a serial number or a batch code. They tell you exactly when the tire left the mold.
The first two digits are the week of the year. Weeks are numbered starting at 01 and go through the end of the year. The last two digits are the last two digits of the year. For example, a code of 0424 means the 4th week of 2024, which is late January 2024.
To find the TIN, look on the outer sidewall of the tire. The DOT letters appear first, followed by a plant code and other characters, and the four-digit date code closes the sequence. For a full guide to every other number and letter on the sidewall, see tire sidewall markings and what every number means.
Reading the Code in Three Seconds
Here is the process, illustrated with a real-format example:
- Find the DOT stamp on the outer sidewall. It looks like:
DOT U2LL LMLR 1319 - Take the last four digits: 1319
- Split them: 13 = week 13 of the year, 19 = 2019
- Week 13 of 2019 is the last week of March 2019 (illustrative: week 13 starts around March 25 in a standard calendar year)
That tire was manufactured roughly six years before a 2025 inspection. Whether that age is acceptable depends on your vehicle manufacturer’s guidance and the tire’s visible condition. Age-based replacement decisions go beyond the date code itself. For a full breakdown of when tread depth and age together signal replacement, see when tires should be replaced based on tread, age, and damage.
Pre-2000 Tires: The Three-Digit Ambiguity
Tires made before the year 2000 used a three-digit date code. The first two digits still represent the week, but the third digit is only the last digit of the year. This creates a serious identification problem. A code ending in 9 could mean 1999, 1989, or even 1979. There is no way to determine the decade from the code alone.
If you find a three-digit date code on any tire, treat the tire as potentially very old. A tire of unknown age with no clear manufacture decade should be inspected by a qualified tire professional before you drive on it.
Why the Manufacture Date Matters for Safety
Tires can become structurally compromised as they age. A tire with plenty of tread depth can still be unsafe if it is old enough.
Because of this, the manufacture date is not just a curiosity. It is a safety data point. Checking the date code on your spare tire is just as important as checking it on your mounted tires, since spares often sit unused for years.
Tread depth alone does not tell you whether the rubber is still structurally sound. The date code gives you the other half of that picture. If you notice uneven wear alongside an older manufacture date, those two signals together strengthen the case for replacement. See what uneven tire wear patterns mean and their causes for help reading wear alongside age.
One Common Misreading to Avoid
Some drivers confuse the date code with other numbers on the sidewall, such as the load index or speed rating. Those appear directly after the tire size (for example, 94H in a size like 235/65R17 94H). The date code only appears at the end of the full DOT TIN string, and it always consists of exactly four digits for tires made in 2000 or later.
Look for the DOT TIN on the sidewall of your tire. It contains the four-digit date code showing when the tire was made.
Frequently asked questions
Why should I check the date code on a spare tire?
Spare tires often sit unused for years. Even with good tread, an old tire can be unsafe. Checking the date code tells you how old the spare is, so you know whether it is still safe to use in an emergency.
Does a newer manufacture date mean the tire is definitely safe to use?
A recent date code is a good sign, but it does not tell you everything about the tire's condition. Always inspect the full tire visually alongside checking the date code.
Can two tires on the same vehicle have different manufacture dates?
Yes. Tires can be replaced at different times, so different tires on the same vehicle can carry different date codes. Checking the date code on each tire individually is the best way to know how old each one is.
Does the date code tell me when the tire was installed on my car?
No. The date code records when the tire was manufactured, not when it was mounted. A tire can sit in a warehouse or shop for months or even years before being sold and installed. The manufacture date is always earlier than, or at best equal to, the installation date.
What should I do if my spare tire has a pre-2000 three-digit date code?
A three-digit code means the tire is at least 25 years old, and possibly older, since the decade cannot be confirmed from the code alone. A tire of that age should be inspected by a qualified tire professional before use. Rubber degrades with age regardless of tread depth, so an old spare may not be safe even if it looks fine.
Sources
- Tire code - Wikipedia · en.wikipedia.org
- Choose the Right Tires for Your Vehicle · Consumer Reports (consumerreports.org)
Prepared from these references and checked against them. References retrieved October 11, 2026.
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