How to tell a tyre's age (DOT code)

When buying tyres most people check size and price, but the manufacture date matters too. Rubber ages; even an unused tyre hardens and starts to crack over the years. The date is in the sidewall code.

Where is the DOT code?

The sidewall carries a string starting with DOT. The first part identifies the plant and tyre type. The date is the last four digits, often in a small separate frame and sometimes only on one side. Check the other sidewall if you can't find it.

How to read it

The first two digits are the week, the last two the year:

• 2324 → week 23 of 2024 (early June)
• 0721 → week 7 of 2021 (mid February)
• 4519 → week 45 of 2019 (early November)

Very old tyres (before 2000) used a three-digit code; such a tyre should not be used anyway.

When is a tyre "old"?

There is no single limit; storage makes a big difference. A tyre kept cool, dark and dry ages far more slowly than one left in the sun. As a rule:

• Prefer a recent manufacture date when buying.
• Check older tyres for fine sidewall cracks, hardening and fading.
• An old tyre with cracked sidewalls is risky under load even with good tread.

When buying

Don't hesitate to ask the dealer for the date; checking the DOT code takes seconds. See how to store tractor tyres and when to replace a tractor tyre.