Tread depth: the legal limit is 1.6mm
UK law requires at least 1.6mm of tread across the central three-quarters of the tyre, around its full circumference. Below that you risk a fine of up to £2,500 and 3 penalty points — per tyre — and an MOT failure.
Legal isn't the same as safe. Wet-weather grip falls away sharply below about 3mm, which is why we — like most manufacturers — recommend replacing at 3mm rather than waiting for 1.6mm.
The 20p test: place a 20p coin in the main tread groove. If the coin's outer band is visible, your tread is likely below 3mm — time to get it checked. We check tread depth free, mobile or in the garage.
Tread depth at a glance
Wet braking distances grow rapidly below 3mm — long before the tyre becomes illegal.
Six signs a tyre needs replacing — whatever the tread
Age & perishing
Rubber hardens and loses grip over time, even in a garage-kept car. Get tyres inspected from 5 years old and replaced by 10 years regardless of tread. The 4-digit date code on the sidewall shows the week and year of manufacture — "2521" means week 25 of 2021.
Sidewall cracking
Fine cracks or crazing in the sidewall mean the rubber is perishing — common on older tyres, caravans and vehicles that stand for long periods. Cracked sidewalls can't be repaired and the tyre should be replaced.
Bulges & eggs
A bulge means the internal cords have failed — usually after a pothole or kerb strike. The tyre can burst without warning at speed. Replace immediately; don't wait for the MOT.
Cuts & exposed cord
Deep cuts, gouges or any visible cord or canvas make a tyre illegal and unsafe. Small shallow cuts may be fine — if in doubt, send us a photo and we'll advise honestly.
Uneven wear
Worn on one edge but fine elsewhere? That usually points to wheel alignment or pressure problems. We'll correct the cause as well as the tyre, so the new one doesn't wear the same way.
Puncture damage
Some punctures can be safely repaired to the BS AU159 standard; others — in the sidewall or shoulder, or after running flat — mean replacement. See our guide: Can my tyre be repaired?
Not sure? We'll check them free.
Free tread and condition checks — at your home, work, or our Blythe Bridge garage. Same-day appointments available.