A GUIDE BY CANNONS AUTOMOTIVE · MORECAMBE, LANCASHIRE · UPDATED AUGUST 2026

The legal minimum tyre tread depth in the UK is 1.6mm, measured across the central three-quarters of the tyre’s width and around its entire circumference. It sounds simple, but every year we see cars in Morecambe fail their MOT — or get pulled over — because a tyre quietly wore past this limit without the driver noticing. Here’s everything you need to know, in plain English.

What is the legal tyre tread depth in the UK?

By law, car tyres must have a tread depth of at least 1.6mm across the central 75% of the tyre and all the way around. This applies to cars, vans up to 3,500kg, and light trailers. Motorcycles and larger vehicles have slightly different rules.

How do I check my tyre tread depth?

The simplest method is the 20p test: insert a 20 pence coin into the tread groove. If the outer rim of the coin is covered by the tread, you’re likely above the legal limit. If the rim is visible, your tyres may be illegal and need checking by a professional straight away. We check tread depth for free on every visit to our Morecambe workshop — no appointment needed for a quick check.

What happens if I drive on illegal tyres?

• Up to £2,500 fine and 3 penalty points per illegal tyre — that’s up to £10,000 and 12 points for four bald tyres
• An automatic MOT failure
• Increased stopping distances, especially in wet weather — a tyre at 1.6mm takes significantly longer to stop than a new one
• Higher risk of a blowout or loss of control

Is 1.6mm actually safe, or just legal?

Legal and safe aren’t quite the same thing. Independent tests consistently show that stopping distances increase sharply once tread drops below 3mm, particularly in the rain. Many tyre manufacturers and safety bodies recommend replacing tyres at 3mm for this reason. Our advice: 1.6mm is the point you must not go below, but 3mm is the point where it’s worth planning a replacement.

Local advice from Cannons Automotive

We fit and check tyres for drivers across Morecambe every week, from our workshop at White Lund Industrial Estate — rated 5.0★ on Google. We stock a wide range of budget and premium tyre brands, and we’ll always give you an honest recommendation based on your car, mileage, and budget rather than pushing the most expensive option. See our Tyre Fitting page for pricing, or book a free tread check alongside your next MOT.

Frequently Asked Questions

Do all four tyres need to be the same tread depth?

Not by law, but it’s strongly recommended — mismatched tread depths, especially between the front and rear axles, can affect handling and grip. We’ll advise you if we spot a significant difference.

Can I check tyre tread depth myself at home?

Yes — the 20p test is a good rough guide. For an exact reading, pop into our workshop and we’ll measure it properly with a tread depth gauge, free of charge.

How often should I check my tyres?

We recommend checking tread depth and pressure at least once a month, and always before a long motorway journey.

Will worn tyres fail my MOT?

Yes — tyres below 1.6mm tread are an automatic MOT failure. It’s one of the most common reasons cars fail their test in Morecambe, and one of the easiest to prevent with a quick check beforehand.