When should I replace my tyres?

Worn tyres are the single biggest tyre-related cause of accidents — and an easy MOT fail and fine. But how do you actually know when yours need replacing? Here are the clear signs, the legal limit, and a 20p coin test you can do on the driveway in 30 seconds.

The quick answer: replace your tyres when the tread drops near 1.6mm (the legal minimum), if you see damage like cuts or bulges, or once they're around 5–10 years old regardless of tread.

The legal minimum: 1.6mm

In the UK, the legal minimum tread depth is 1.6mm across the central three-quarters of the tyre, all the way around. Drive on less and you risk an MOT fail, a fine of up to £2,500 per tyre and 3 penalty points each. Most experts recommend replacing at 3mm though, because wet grip drops off sharply below that.

The 20p test

No gauge? Use a 20p coin. Pop it into the main tread grooves at several points around the tyre. If the outer band of the coin is hidden by the tread, you're likely above the limit. If you can see the outer band, your tread is getting low and it's time to get the tyre checked or replaced.

Five signs it's time to replace your tyres

1. Low tread. Below 3mm your wet braking suffers; below 1.6mm it's illegal. The 20p test or the tyre's built-in wear bars will tell you.

2. Cracks, cuts or bulges. A bulge means internal damage and a blowout risk — replace immediately. Cracking in the sidewall is a sign of age or perishing.

3. Uneven wear. Worn more on one edge than the other often points to a wheel alignment problem; worn in the centre or both edges can mean incorrect pressures.

4. Vibration. A shudder through the steering can mean a tyre is damaged, out of balance or coming apart internally — get it checked.

5. Repeated punctures or slow leaks. A tyre that keeps losing air may not be safely repairable. Sometimes replacement is the sensible call — see puncture repairs.

Does tyre age matter, even with good tread?

Yes. Rubber hardens and perishes over time, so even a tyre with plenty of tread should be checked from around 5 years old and is generally replaced by 10 years, whatever the tread looks like. You can find the age on the sidewall — the last four digits of the DOT code are the week and year of manufacture.

Should you replace in pairs or all four?

If only one tyre is damaged, you can replace just that one — ideally matching the others on the same axle. When several are low, replacing them together keeps grip even and handling predictable. We'll give you honest advice when we see them; there's no upsell.

Which tyres should you replace them with?

That depends on your car and mileage — see our guide to budget vs premium tyres, or just send your reg and we'll recommend the right option. Curious on price? Here's how much mobile tyre fitting costs.