Tire age and the DOT code: how to tell when tires are too old
How to read the date on your tires and know when age, not tread, means replacement
Most drivers know to replace tires when the tread wears down. Fewer know that tires also wear out with age. The rubber slowly dries and hardens over time. Cracks can form inside the tire where you cannot see them. An old tire can look fine and still fail at highway speed.
Every tire sold in the United States carries a code that tells you exactly how old it is. This guide shows you how to read it and when age alone is a reason to replace.
Find the DOT code
Look at the sidewall of your tire for the letters “DOT.” A string of letters and numbers follows. This is the Tire Identification Number. Federal rules require it on every tire [1].
The last four digits are the date code. The first two digits are the week. The last two are the year [2].
Comparison compiled by Safety Behind the Wheel Foundation
Reading a tire date code
| Last four digits | What it means |
|---|---|
| 0519 | 5th week of 2019 (early February) |
| 2321 | 23rd week of 2021 (early June) |
| 4524 | 45th week of 2024 (early November) |
Source: Based on the tire identification number format described by NHTSA and Edmunds [1, 2].
The full code is sometimes printed only on the inner side of the tire. You may need a flashlight, or to look from under the car.
If you see only three digits, the tire was made before 2000 and is far too old to use [2].
Why old tires are risky
Rubber breaks down over time through a process like drying out. Heat speeds it up. Federal research found that tires age faster in hot climates [2]. Sunlight, ozone and long periods of sitting still can also harm tires.
Aging tires are more likely to have the tread separate from the rest of the tire. That can cause a sudden loss of control, especially at highway speeds or with a heavy load.
How old is too old
There is no federal age limit for passenger car tires. NHTSA has not set one, and it defers to vehicle and tire makers [2]. Their advice:
- Several carmakers, including Ford, Nissan and Mercedes-Benz, say to replace tires 6 years after they were made, no matter how much tread is left [2].
- Tire makers such as Michelin and Continental say to replace tires no later than 10 years after they were made. Michelin also urges a yearly inspection after the fifth year [2].
Your owner’s manual may give a specific number. Follow it. When in doubt, have a tire shop inspect tires older than 5 years every year.
Do not forget the spare
A spare tire that has never been used is still aging. If it is mounted on a wheel, it counts as in service [2]. Spares stored under a truck or SUV face heat, dirt and road spray. Check the spare’s date code too. A 12 year old spare may fail when you need it most.
Buying tires: check the date
Tires can sit in warehouses for a while before sale. When you buy new tires, check the date code before they go on your car. A tire made within the past year or so is a reasonable expectation for “new.” Ask the shop if the date looks old.
Be careful with used tires. You often do not know how they were stored or whether they were damaged or repaired.
Tread and pressure still matter
Age is one test. Tread and pressure are the others.
- Tread depth. Most states set the legal minimum at 2/32 of an inch. Use the penny test: put a penny upside down in the tread. If you can see all of Lincoln’s head, the tread is too worn.
- Wet roads. Tires lose grip in rain well before they hit the legal minimum. Many safety groups suggest replacing tires at 4/32 of an inch. A quarter upside down shows that depth at the top of Washington’s head.
- Pressure. Check monthly with a gauge when tires are cold [1]. Use the pressure on the sticker inside the driver’s door, not the number on the tire sidewall.
Tire recalls
In 2025, there were 16 tire recalls affecting about 145,000 tires [3]. Many owners never hear about a tire recall because they never registered their tires.
- When you buy tires, ask the seller to register them, or register them yourself with the tire maker
- You can search for tire recalls on NHTSA’s website using the Tire Identification Number [1]
- Keep a photo of each tire’s full DOT code
Warning: Replace a tire right away if you see bulges, deep cracks, cuts, exposed cords or a vibration that was not there before. These can signal a tire about to fail.
Checklist: tire health check
Checklist from Safety Behind the Wheel Foundation
- I found and read the date code on all five tires, including the spare
- None of my tires is older than my owner’s manual allows
- My tread passes the penny test, and I plan to replace at 4/32 inch
- I check tire pressure once a month
- My tires are registered with the maker
- I checked NHTSA for tire recalls
Frequently asked questions
My tires have lots of tread but are 8 years old. Should I replace them?
Many carmakers would say yes. At a minimum, have a tire professional inspect them now and every year. In a hot climate or on a vehicle that carries heavy loads, replacement is the safer choice.
Do tires on a car that sits a lot age faster?
Tires that sit in one spot for long periods can develop flat spots and cracking. Age still counts, even with low miles.
Is there a law against selling old tires?
There is no federal age limit on selling passenger tires. A few states have considered rules. Always check the date yourself.
Related articles
Sources and further reading
- 1National Highway Traffic Safety Administration. “Tires.” nhtsa.gov/equipment/tires
- 2Edmunds. “How Old and Dangerous Are Your Tires?” edmunds.com/…/how-old-and-dangerous-are-y…
- 3National Highway Traffic Safety Administration. “2025 Annual Recalls Report.” nhtsa.gov/…/2025-annual-recalls-report.…
This article reflects the safety priorities of vehicle maintenance and tire safety. It is general education, not mechanical advice. Follow your owner’s manual and a tire professional’s inspection. Reviewed November 2026.
Special thanks to our contributors
We appreciate the professionals, experts, and community members who share their knowledge and perspectives to help make this resource better. Your insights are always welcome and appreciated.
Have professional expertise, firsthand experience, or a perspective that could make this resource better?
We welcome your input. Your knowledge and experience can help us make this resource more useful, accurate, and meaningful to the people who rely on it.
Thank you. Your contribution is on its way.
We’re grateful you took the time to share your knowledge with us. Our team reviews every contribution with care. If it helps improve this resource, we’ll update the page and recognize you the way you chose.
Keep learning
Safe Driving Resource Center
Guides, self-checks and articles for drivers, parents of new drivers, and families recovering after a crash.
