Tire age & DOT date code guide

What is the tire DOT date code?

The last four digits of a complete DOT Tire Identification Number show the manufacturing week and year. Age alone cannot confirm that a tire is serviceable: inspect pressure, wear, damage and performance, and follow the tire and vehicle maker. NHTSA says some makers recommend replacement at 6–10 years; Michelin recommends annual professional inspection after five years and replacement by ten; Continental advises removing tires over ten years, including spares.

DOT date code

Enter the 4-digit DOT date code from your tire sidewall — the week and year it was made.

Where to find the DOT code

The DOT code is moulded into the sidewall of the tire, usually on the inner sidewall (facing the vehicle). Look for the letters DOT followed by a string of letters and numbers. The last four digits are the date code. Example:

DOT U2LL LMLR 2318 → manufactured in week 23 of 2018.

DOT date code examples

Last 4 digits, Week, Year, Meaning
Last 4 digits	Week	Year	Meaning
2318	23	2018	Week 23 of 2018 (approx. June 2018)
0421	04	2021	Week 4 of 2021 (approx. January 2021)
5223	52	2023	Week 52 of 2023 (approx. December 2023)

Tire age replacement guide

Age, Condition, Recommended action
Age	Condition	Recommended action
< 5 years	No age-only verdict	Continue pressure, wear and damage checks; age alone does not confirm serviceability.
5–6 years	Increase scrutiny	Michelin recommends annual professional inspection after five years of service.
6–10 years	Maker guidance varies	Follow the exact tire and vehicle-maker limit; damage, wear or performance changes can require earlier replacement.
> 10 years	Precautionary replacement benchmark	Michelin recommends replacement by ten years; Continental advises removing tires over ten years, including spares.

What causes old tires to fail?

Oxidation — rubber reacts with oxygen and UV over time, causing the polymer chains to harden and crack.
Ozone cracking — visible as fine surface cracks on the sidewall or between tread blocks. Accelerated by heat, UV exposure, and ozone.
Belt separation — the steel or fabric carcass can delaminate from the tread in aged tires, causing sudden blowout.

Pre-2000 tires: 3-digit date codes

Tires made before 2000 used a three-digit code: first two digits = week, third digit = year of the decade (e.g., 234 can mean week 23 of 1994 or 1984). Any such tire is far beyond the manufacturer age benchmarks cited here; remove it from road service and have the wheel and spare plan checked professionally.

Tire-age sources reviewed

The DOT decoding and age boundaries above were checked against current government and tire-maker guidance. These are not a universal legal limit.

Checked: 2026-08-21

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Last reviewed: 2026-08-21