The legal minimum tyre tread depth for a car in the UK is 1.6mm across the central three-quarters of the tyre, around its whole circumference. Below that, the tyre is illegal. Most tyre experts, and we, suggest replacing before they reach 3mm, because grip in the wet falls away well before the legal limit.
Checking takes a minute, and you do not need special tools. Here is how.
The fine
Driving on an illegal tyre can lead to a fine of up to £2,500 and three penalty points for each tyre. It is also a straight MOT fail. More importantly, a worn tyre takes much longer to stop on a wet road.
How to check with a 20p coin
- Take a 20p coin and push it into the main grooves of the tyre.
- Look at the outer band of the coin. If you can see all of it, the tread may be below 3mm and it is time to think about replacing.
- Check across the tyre, not just in one place, and on all four tyres.
- For a firm figure, ask us. We use a tread depth gauge, and it takes a minute.
The 20p test is a rough guide for the 3mm mark. It is not a measure of the legal limit.
Other things to check
- Cracks, cuts or bulges in the sidewall. These can fail a test, whatever the tread.
- Uneven wear, such as one edge worn more than the other. It often points to alignment or suspension problems.
- The pressure, which should match the figure in your handbook or on the door pillar.
- The age. Even unused tyres perish. Many makers advise replacing at around ten years.
- The spare, if you have one.
When to replace
At 3mm if you can, particularly if you drive on wet or fast roads. At 1.6mm at the absolute latest. Replace tyres in pairs on the same axle at least, and fit the newer ones to the rear for stability.
See our repairs page for tyres, or book online and tell us the make and model.
Quick answers
What is the legal tyre tread depth in the UK?
1.6mm across the central three-quarters of the tread, around the whole tyre.
Is 2mm of tread safe?
It is legal, but grip in the wet is already much reduced. Replace before it gets there if you can.
Does the 20p test show the legal limit?
No. It indicates 3mm, which is the point at which most experts suggest replacing.
Do you fit tyres?
Yes. We supply and fit tyres for all makes and models.