What is the minimum legal tyre tread depth? Halfords calls for review

The CEO of the motoring and cycling retailer has called for an 'urgent review' into the legal limit for tyre tread depth following a new study. 

Worn but legal tyres take almost 90 feet longer to stop compared with vehicles with tyres in good condition when driving at 70mph, according to research conducted by Professor Peter Wells of the Centre for Automotive Industry Research at Cardiff University.

The Halfords commission study found that this distance equates to a basketball court or the length of seven cars.

The CEO of Halfords has called for an urgent review into the legal limit for tyre tread (PA) (Image: PA)

Graham Stapleton, CEO of Halfords, commented: “We need to get a grip on tyre safety. The current legal limit for tyre tread depth is too low and it’s putting millions of motorists at risk.”

What is the legal minimum tyre tread depth in the UK?

The current legal minimum amount of tread for a car tyre in the UK is 1.66mm.

However, the legal limit varies by vehicle for example most larger vehicles require a 1.0mm through a continuous band and motorbikes of 50cc and over also need a 1.0mm throughout a continuous band.

For a further breakdown and guidance, visit the AA website.

However, according to the study, the stopping distance of tyres of 4mm tread compared to the legal limit in the same wet, winter driving conditions is a staggering 36%.

In other words, an additional 89 feet or 27 metres.

Cars with 1.66mm tyre tread would pass an MOT despite the results of this study suggesting that their performance is significantly compromised.

Halfords also asked Cardiff University to analyse the stopping distance of worn tyres against another factor that is known to increase stopping distance.

Researchers examined the impact of drink driving and found that driving with worn tyres actually increases stopping distance seven times as much as being under the influence of alcohol.

Graham Stapleton, CEO of Halfords, continued: “Every year we advise huge numbers of UK motorists that their tyres are dangerously low on tread, but unfortunately many drive away assuming that, if they’re legal, they must be fine. But the reality is that their safety is already significantly compromised, and this will only increase as they experience more wear.

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"Any tyres that receive a warning are likely to be illegal with just a few thousand more miles of motoring.

"A tyre with just 1.6mm of tread could be one small lock up or pothole away from being illegal and this could even happen on the way back from the test centre, but the tyres may not be checked again until their next MOT.

"This study clearly demonstrates that current tread limits are just too low given how much grip is reduced, even when within legal limits.”

How can I check my tyres?

You can sign up for a free tyre check any time at any Halfords or National Tyres and Autocare garage.

Drivers can also use a tyre tread depth gauge to help you get an accurate measurement, find out more via the Halfords website.

RAC also suggests taking a 20p coin and inserting it into the grooves of your tyre. 

If you can't see the coin's outer band, your tyres are over the legal limit.

However, if you can see this section on the coin, your tyres may be unsafe and below the legal limit.

RAC recommends that you carry out the 20p coin check every two weeks and before big journeys.

For more information or to learn how to sign up for Halford's Motoring Club ( where you can get a 10% discount on MOTs, visit the Halfords website.