How old are my tyres, and does age matter as much as tread?
Every tyre carries its week and year of manufacture in a four-digit code. How to read it, why a nearly new-looking tyre can still be unsafe, and where age matters most.
- Difficulty
- beginner
- Time
- 10 min
- Read
- 4 min
- Safety
- caution
Short answer
Look for a four-digit number in an oval on the sidewall — the first two digits are the week and the last two the year, so 3221 means the thirty-second week of 2021. Tread depth tells you how much tyre is left; the date tells you how long the rubber has been ageing. A tyre with legal tread but a decade of age, cracking or a caravan's worth of standing time is the one to worry about.
Rubber is a material that ages whether or not it is used. Ultraviolet light, ozone, heat cycling and simply time break down the compounds that keep it flexible, which is why a spare that has never touched the road can be unfit while looking perfect. Tread depth measures wear; it says nothing about the condition of the material. Both matter, and in Britain the legal requirement covers only one of them — which is why age is worth knowing about.
Safety
Step by step
- Find the DOT code on the sidewall.Look for a sequence beginning DOT followed by letters and numbers, ending in a four-digit group, often inside a small oval. It may be on the inner face of the tyre, so you may need to look from underneath or turn the wheel to full lock.
- Read the four digits as week and year.The first two digits are the week of the year, the last two are the year. 0824 is the eighth week of 2024. Anything with a three-digit code is from before 2000 and should have been replaced long ago.
- Check the tread depth separately.In the UK the legal minimum for cars is 1.6 mm across the central three-quarters of the tread and around the whole circumference. Most tyres have wear indicator bars moulded into the grooves at that depth — when the tread is level with them, the tyre is at the limit.
- Inspect the rubber itself, not just the numbers.Fine cracking in the sidewall or at the base of the tread grooves — sometimes called crazing or perishing — is the visible sign of an aged tyre. So is a hard, shiny look to the rubber. Either means replacement regardless of what the tread gauge says.
- Pay particular attention to the spare and to little-used vehicles.Spare wheels, caravans, trailers, classic cars and second cars all accumulate age without accumulating wear. This is where age-related failures actually happen.
- Check the date when buying tyres, not just after.Tyres are sometimes sold from old stock. Asking the date of manufacture before fitting is entirely reasonable, and a well-run fitter will not mind.
Common mistakes
- Treating 1.6 mm as a target rather than a limit — It is the point at which a tyre becomes illegal, not the point at which it stops working well. Wet performance deteriorates considerably before that.
- Assuming an unused spare is fine — A spare ages on exactly the same clock as the tyres doing the work, and it is the one you will be relying on at the roadside in bad weather.
If it doesn't work
Plenty of tread but fine cracks in the sidewall
Cause: Age and UV exposure — Fix: Replace them. The structure is degrading and tread depth is not measuring that.
Tyres are different ages across the car
Cause: Replaced in pairs or singly over time — Fix: Not a fault in itself. What matters more is that the two tyres on the same axle match in type and condition, which affects handling and braking balance.
Car has stood for a long time and steers oddly for the first few miles
Cause: Flat spots from standing — Fix: Usually eases as the tyres warm. If it does not, or if there is visible deformation, the tyres have taken a set and need replacing.
Tread is above 1.6 mm but grip in the wet has got noticeably worse
Cause: Reduced tread depth long before the legal limit — Fix: Wet braking and aquaplaning resistance fall off well above the legal minimum. Many drivers replace at around 3 mm for that reason, which is a judgement rather than a requirement.
Questions people ask
Is there a legal age limit for tyres?
For ordinary cars in Great Britain there is no general age limit — the legal requirements cover tread depth and condition. Age limits do apply to tyres on some heavier vehicles and buses. For a car it is a condition question, which is why the visual inspection matters as much as the code.
How old is too old?
There is no single answer, and it depends heavily on storage, climate and use. Many manufacturers suggest inspecting annually beyond about five years and being cautious beyond around ten. The visible condition of the rubber should override any number.
Where exactly is the code?
On the sidewall, usually near the rim, and often only on one side of the tyre — which may be the side facing inwards. Turning the steering to full lock makes the inner face of the front tyres visible.