Every tyre sold in the US has a DOT code on its sidewall. The code starts with the letters DOT and identifies the manufacturer, the plant, and the tyre type. The last four digits show the week and year the tyre was made, which tells you the tyre’s age. This guide explains how to find the DOT code on a Bridgestone tyre, how to read the date code, and why tyre age matters.
Where to find the DOT code
The DOT code is moulded into the sidewall of the tyre, usually on the outer side when the tyre is fitted to the vehicle. It is often near the rim, so you may need a torch and a clean cloth to read it. On some tyres the code appears on both sidewalls, and the full code is normally on the sidewall that faces outward.
How to read the date code
The date code is the last group of numbers in the DOT code. For tyres made since 2000, it is four digits: the first two show the week of manufacture, from 01 to 52, and the last two show the year. For example, 2419 means the 24th week of 2019. Tyres made before 2000 have a three-digit date code, which is harder to read and usually means the tyre is well past its normal service life.
Why tyre age matters
Rubber ages even when a tyre is not used. Heat, ozone, sunlight, and time all cause the compound to harden and crack, which can reduce grip and make the tyre more likely to fail. Many manufacturers advise replacing tyres after a set number of years, often around six to ten years from the date of manufacture, regardless of tread depth. Check the guidance for your specific tyre.
Checking tyres you are buying
When buying tyres, check the date code before fitting. Ask the supplier for tyres made within the last year or two where possible. A new tyre that has been stored for a long time can already be several years old, so the date code is the best way to tell how fresh it is.
Storing and caring for tyres
Store tyres in a cool, dry, dark place, away from direct sunlight, heat sources, oil, and fuel. Keep them upright or stacked neatly so they do not deform. Check the sidewall regularly for cracks, bulges, and cuts, and replace any tyre that shows damage, whatever its age.
Frequently asked questions
Do all tyres have a DOT code? Tyres sold for road use in the US must carry a DOT code. Check the sidewall if you are unsure.
Where is the serial number on a Bridgestone tyre? The DOT serial number is on the sidewall, with the date code at the end of it.
Can I use a tyre that is more than ten years old? Many manufacturers advise against it, even if the tread looks good. Check the guidance for your tyre and have a qualified fitter inspect it.
Get help with your tyres
For more on choosing and caring for tyres, read our tire guides. If you are not sure how old your tyres are or whether they should be replaced, contact us and we will help you check.