A tyre can be unsafe from age alone, even with plenty of tread left. Rubber hardens and cracks over time, reducing grip and raising the risk of sudden failure. Most manufacturers recommend replacing tyres at 5 to 10 years old regardless of tread, and many advise against fitting any tyre that's already over six years old. Age, not just wear, is what decides when a tyre's time is up.
The good news is that every tyre carries its own birth certificate. Here's how to find and read it, why age matters as much as tread, which tyres are most at risk, and where the law now stands.
How to read the DOT date code
Every tyre has a DOT code on the sidewall ending in four digits. The first two are the week of manufacture; the last two are the year. So "2624" means the 26th week of 2024. If you only see three digits, the tyre was made before 2000 and should be replaced immediately, it's far too old to trust. The code is sometimes on the inner sidewall, so you may need to look on both sides or have the wheel turned.
The four digits sit at the end of the longer DOT string, often inside a small oval. A torch and a damp cloth help, because the moulding is shallow and fills with dirt. Write the four dates down once and keep them in the glovebox, then you only need to check the spare.
Why age matters as much as tread
Heat, sunlight and oxygen slowly break down rubber compounds in a process called oxidation. An old tyre may look fine but have lost flexibility, leading to cracking and, in extreme cases, tread separation at speed. This is why a tyre with deep tread can still be dangerous if it's old, the rubber simply doesn't grip or hold together the way it did. Cars that cover low mileage are most exposed, because their tyres age out long before the tread wears down.
Where to look beyond the date
Some tyres age out long before they wear out, so these are the ones to check first:
- Spare wheels: often the oldest tyre on the car, sitting unused for years.
- Caravans and trailers: check these every season, as many fail on age, not mileage.
- Part-worn tyres: can be deceptively old; see our guide to part-worn risks.
- Classic and low-mileage cars: the tyres may be a decade old despite looking barely used.
Alongside the date, look for fine cracking in the sidewall and tread grooves, which is a clear sign the rubber is perishing.
The law on old tyres
For cars there's no fixed legal age limit, but a perished or cracked tyre can be illegal on condition and fail the MOT. For larger vehicles the law is explicit: tyres over 10 years old are banned from the front axles of buses, coaches and HGVs, and from single-fitted wheels on minibuses, a rule the Government introduced on safety grounds after research into ageing tyres. The same ageing process affects car tyres, which is why the manufacturer guidance to replace at 5 to 10 years is worth following.
Signs a tyre is ageing, whatever the date says
The date code tells you how old a tyre is; the rubber tells you how it has aged, and the two do not always agree. A garaged tyre can be sound at seven years, while one that has sat in the sun on a driveway can be perishing at four. Look for these.
| What you see | Where | What it means |
|---|---|---|
| Fine web of surface cracks (crazing) | Sidewall, especially the lower part | Rubber is oxidising; early ageing. Monitor closely, plan replacement |
| Deeper cracks you can catch a fingernail in | Sidewall or tread grooves | Advanced perishing. Replace |
| Cracks at the base of the tread blocks | Inside the grooves | Tread may separate. Replace |
| Hard, glossy or greyish rubber | All over | Compound has lost its oils and flexibility, so grip is down |
| Bulge or ripple | Sidewall | Internal structure failing. Do not drive on it |
Cracking is also an MOT matter. A tester can fail a tyre whose cords are exposed or which is cut or perished deep enough to reach the cords, and the general condition rules are on GOV.UK. Our guide to cracked and perished tyres shows what each stage looks like.
What makes tyres age faster
Sunlight, heat, ozone and standing still are the main enemies, which is why the same tyre can age at very different rates on two cars. You cannot stop the chemistry, but you can slow it.
- UV and heat. A car parked in full sun all day, or a tyre stored by a radiator, ages faster. Shade and a garage help.
- Standing unused. Rubber contains waxes and oils that migrate to the surface as the tyre flexes and protect it. A tyre that never rolls loses that protection and cracks sooner.
- Under-inflation. A soft tyre flexes more and runs hotter, which accelerates ageing as well as wear.
- Solvent-based tyre dressings. Some glossy products dry the rubber out. If you want the look, use a water-based product sparingly.
- Ozone. Electric motors and some workshop equipment produce it; storing tyres next to them is a known cause of cracking.
If you store a seasonal set, keep it clean, dry, out of the light and away from motors, ideally in bags. Seasonal tyre storage covers how to do that properly.
New tyres are not always new
A tyre sold as new can already be a year or two old, because tyres are made in batches and sit in warehouses. There is no UK legal cut-off for selling a stored tyre as new, so the date code is your check.
Tyre makers generally accept that a properly stored tyre keeps its full performance for several years after manufacture, and a tyre a year or two old is normal stock. What you want to avoid is paying full price for one that has already used up a large share of its sensible life.
When you buy, ask for the DOT date before the tyre is fitted, and check it yourself on delivery. A reputable fitter will tell you without fuss. Part-worn tyres are the bigger risk here, because an old part-worn is often sold on tread depth alone.
Caravans, motorhomes and trailers
Tyres on caravans, motorhomes and trailers almost always age out rather than wear out, so replace them on age and condition, not tread. They spend months standing, often in the sun, carrying a heavy static load on one patch of tread.
Caravan industry guidance is generally more cautious than for cars, often recommending replacement at around five years whatever the tread looks like. Motorhome tyres should meet the load index for a fully loaded vehicle, and towing puts a heavy demand on the car's rear tyres too.
Before the first trip of each season, check the date codes on every tyre including the spare, look for cracking on the sidewalls, and set pressures for the load you will carry.
Not sure how old your tyres are?
Our fitters can check the DOT dates and condition when we come to you, including the spare, which is the one most people forget. If a tyre's aged out, we can supply and fit a fresh one where the car is parked, across London and the Home Counties.
