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What makes tyres illegal?

28th October 2021

An illegal tyre refers to when a tyre does not meet the UK regulations that constitute as ‘safe’ or ‘roadworthy’. This could mean that the tyre is a safety risk, potentially risking harm to yourself and others, and compromising the performance of your vehicle. If you are found driving an illegal tyre, you may receive points on your licence and/or substantial fines – so it’s definitely one to avoid!

Tyres are checked within an MOT test – but, if they are found to be illegal, they will cause you to fail your MOT test, so it’s important to be clued up on what’s legal and what’s not. There are a number of illegal tyre examples to watch out for – such as incorrect tyre pressure and using inappropriate tyres for your vehicle, which is why we’re here to help you ensure your tyres remain legal.

Examples of illegal tyres

1. Tyre tread depth

Are you familiar with the legal tyre tread depth limit in the UK? Although this is one of the staples of keeping your tyres legal, many people are unsure of what the limit is – thus, could be driving around on tyres which are actually illegal.

Ensure that your tyre tread depth is above the minimum limit, 1.6mm, across the central 3/4 of the tyre width. However, it’s strongly recommended that tyres should be replaced at around 3mm tread depth – as it’s suggested that this level of tread depth will still be compromising your performance to some degree. If you’re found driving on tyres which are lower than 1.6mm, you could risk 3 penalty points, and a fine of £2,500 per illegal tyre – so ensure you check your tyre tread depth at least once a month.

2. Mixing different tyres on your car

As a general rule, mixing different tyres on your vehicle is not advised. However, this may not always be possible – for example, you could mix tyre brands and tread patterns. In order to ensure your tyres are legal, you should ensure to never mix tyres designed for different seasons (for example, having winter tyres on the rear and summer tyres on the front).

This is extremely dangerous – as it causes the two different sets of tyres to counteract against each other. These tyres have been designed specifically for their season – so, combining two from opposing seasons can risk safety and performance of your vehicle, as this would then be classed as an illegal tyre.

3. Uneven or excessive tyre wear

One of the most common offences of illegal tyres, uneven or excessive tyre wear can directly affect the safety and performance of your vehicle. Uneven tyre wear refers to areas of the tyre which have been worn down dangerously – for example, uneven wear across the circumference of the tyre.

If you are found with illegal tyres, this can sometimes lead to points on your licence or fines – as excessive tyre wear can cause weak spots in the tyre which then could lead to a tyre blowout. Suspect your tyres may have uneven wear? Book in with an expert now.

4. Inaccurate tyre pressure

Did you know, having incorrect tyre pressure is actually an offence? This is because inaccurate tyre pressure can not only damage your tyres, but it can also affect the safety and performance of the vehicle.

  • Underinflated tyres – if your tyres are not inflated enough, handling is affected – meaning that responding to directional changes may be impacted due to an increased grip on the road surface.
  • Overinflated tyres – this could lead to skidding on the road, as well as potential tyre blowouts. Overinflated tyres lead to an increase in contact with the road surface, which then reduces the grip of the road itself, compromising safety and efficiency.

Check your tyres are inflated to the appropriate pressure from our guide – or book in for a free tyre check today.

5. Driving tyres inappropriate for your vehicle

Although this type of offence is less common, it’s arguably one of the most dangerous to employ. This refers to if you are using the wrong tyres for your vehicle, for example, if a car designed to be fitted with 4x4 tyres, such as a Jeep or a Land Rover, was fitted with small tyres meant for a Smart Car. This would not only compromise the performance of the vehicle itself, but also wouldn’t adhere to health and safety regulations – putting the driver, passenger and other drivers on the road at risk.

Want to ensure your tyres are legal? Brush up your knowledge on everything UK car tyre law related with our handy guide. And, of course, you can always visit us in store – locate your nearest branch today to book in with our expert team to ensure your tyres are legal and performing in the best way possible.