Checking the tread depth of a tyre is one of the easiest and quickest things you can do and could save you a small fortune in the long run – it could also save your life!

In a 2013 survey, almost two thirds of motorists did not know that a legal tread depth limit existed, lack of awareness remains a problem so we’re here to make sure you’re in the know when it comes to staying safe and within the law.

The legal minimum tread depth in the UK is 1.6mm across 75% of the circumference of the tyre – this means the central 75% of the tread must be 1.6mm or more over the circumference of the tyre. If you are found driving on tyres below the legal limit, the police can issue fines of up to £2,500 and 3 penalty points for EACH illegal tyre!

Not only can low tread depth result in hefty fines, penalty points and MOT failure, vehicle handling is also compromised and stopping distances can increase. Though the legal limit is 1.6mm many experts within the automotive industry acknowledge the decline of tyre performance once tread depth reaches 3mm.

Now you know the legalities – how can you make sure your tyres have plenty tread and are safe to continue using?

There are a few ways to check your tread depth, the most accurate is to use a tread depth gauge, a small tool design specifically to measure tyre tread depth. These are inexpensive to buy and can be a useful tool to keep track of your tyre tread.

Another way to check your tyres are legal is to look at the wear indicator on the tyre its self, these small bumps in the tread grooves indicate when a tyre has reached the legal limit. If the tread is in line with these grooves the tyre is now illegal to be used on the road – so best to think about replacing your tyres when you see they are close to these wear indicators.

Wear Indicator in Tread Groove

The third and simplest way to check your tread depth is the 20p test. This method is one of the quickest ways to check that your tyres are legal and safe to use.

To do this, simply take a 20pence piece, insert it into the tread groove on your tyre and look at it from a level height. If the outer band (as marked in green below) is below the tyre tread, your tyres are above the legal limit and safe to use. However, if the outer band is showing then your tyres could be unsafe and will require changing.

It is suggested that drivers check their tread depth regularly, we recommend doing the 20p test every two weeks as well as checking all tyres before a long journey. If you’re checking your tyres because you have an MOT coming up, read our MOT Test Guide for more simple checks you can do to make sure your car passes first time!

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