The Guide to Checking Your Tyre Depth

Checking your tyre depth is one of the easiest but also one of the most important you can carry out. Having tyres below the minimum legal tread depth not only brings you closer to a potential accident, but also could see you losing your licence and faced with a £10,000 fine if all four tyres are illegal.

What’s the Legal Minimum Depth of Tread for Car Tyres?

The legal tyre tread depth is 1.6mm through a continuous band in the central three-quarters of the tyre, and around the entire outer circumference. 

How to Check and Measure Tyre Tread Depth

There are a few ways that you can check your tyre tread depth, and for the easiest way to test, make sure you have parked your car with the steering fully locked across so you can get a better view of the tyre.

  • Tyre Wear Indicators
    Most tyres come with a wear indicator built into the tread. Simply look for “TWI” or a similar symbol along the sidewall. In line with this symbol will be a series of blocks within the tread. If the tread is level with these then your tread is at 1.6mm and your tyre needs replacing immediately.
  • Tyre tread gauge
    Coming in a variety of forms, from basic cards to a digital gauge, simply place the measuring tool into the tyre’s groove. The readout will show you exactly how deep your depth is.
  • The 20p test
    A typical 20p piece comes with an outer band as a design, and this band is just under 3mm wide. Simply place the coin into your tread’s groove and if you cannot see any of the outer band then you know your tyre is well above the legal limit. If you can see any of the band then it’s worth getting them checked with a more accurate gauge, and potentially getting them replaced.

How Much Tread is on a New Car?

Most tyres are manufactured with between 8-9mm of tread on them, but this will wear away the more you drive, so constant checking is a must to ensure your car is not only legal, but safe to drive.

How Long Will 3mm Tyre Tread Last?

How long a tyre with 3mm tread will last before it is below the 1.6mm limit depends on a number of factors, including, fairly obviously, how far you’ll be driving on them. If you drive particularly erratically such as cornering quickly or braking sharply then they will wear out much quicker, likewise if you drive in the city more than on the motorway you’re likely to be wearing your tyres quicker than if you have the consistent speed and straight lines of driving on motorways.

With everything taken into account, on average it will take around 10,000-20,000 miles to wear a tyre with 3mm of tread down to 1.6mm. You will find that most tyre retailers will suggest you replace your tyres after they reach 3mm as the performance begins to drop dramatically once they reach this point, while the AA recommends you change your tyres before they drop below 2mm.

How Many Miles Per 1mm of Tyre Tread?

On average, you should get approximately 1,000-4,000 miles out of one millimetre of tyre tread, but everything from your driving style to the road and weather conditions can have an effect on how fast it’ll wear. Tyres will also wear much faster if you’ve bought a budget set of tyres against a more premium set.

What Could Happen if Your Tyre Tread is too Small?

Driving with low tread on your tyres is not only illegal, but incredibly dangerous. Driving with minimal tread means that you’ll have a lot less grip on wet roads, making you more prone to aquaplaning, gives you less traction on icy roads or snow, and increases your stopping distance considerably. You’re also driving around with a much greater chance of a puncture or blowout.

Driving with illegal tyres can land you a £2,500 fine and three points on your licence. Per tyre. If all of your tyres are found to be illegal, you’ll be slapped with a £10,000 fine and handed 12 points, enough to be instantly disqualified from driving. So for the sake of the cost of a new tyre, is it worth the risk?

For more hints and tips on keeping you and your vehicle on the road, including how to understand tyre sizes, visit our Car Care hub where we guide you through everything you’ll need to know during your driving career.

If your car has recently been in an accident recently as a result of poor tyres and you’re now looking at a hefty repair bill, then maybe you’ll find scrapping a better option. Scrap Car Comparison can guarantee you the very best price going for your car, and we’ll even get it collected from you for free. Get started today using our quick and easy online quote generator and see just how much your car could be worth.

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