24th March 2022

What Things Can Make Your Tyres Illegal?

Most drivers know that driving with damaged or excessively worn tyres can be incredibly dangerous. If your tyres don’t meet certain requirements, however, they could also be breaking the law. It is therefore essential to check your tyres regularly and to know what to look out for. Below we list five things that could make your tyres illegal.

Low tread depth

The ‘tread’ is the name given to the rubber around a tyre’s circumference that makes contact with the road. As tyres are used, their tread eventually wears down meaning that the tyre will need to be either retreaded or replaced. According to UK law, the minimum tyre tread depth is 1.6mm across the central ¾ of the tyre’s face and around its circumference.

There are several ways that you can check a tyre’s tread depth. Firstly, some tyre manufacturers incorporate an indicator bar into the design of their tyres which will become visible when the tread depth reaches 1.6mm. Special tread measuring tools can also be purchased, or you could use the ‘20p test’. Slot a 20p coin into the grooves of the tyre – if the outer rim of the coin can be seen, it is likely that the tyre is ready to be replaced.

Excessive tyre wear or damage

Tyres will naturally wear out over time, and as a tyre becomes excessively worn it also becomes dangerous. A well-worn tyre can develop weak spots, making it vulnerable to blowout. You should inspect your tyres frequently looking out for any visible signs of wear such as bulges, cracking or any damage to the tyre’s sidewall. If you spot any of these, it is important to get your tyres checked by a professional straight away.

Mixing tyre ply

Tyres are constructed from a lattice, or grid, of layered cords, overlaid with rubber. A tyre’s ‘ply’ refers to the direction the tyre’s inner lattice runs in, and how this has been overlaid. Tyres with different plys have different characteristics and therefore handle differently, which is why it’s important to never mix tyres with different plys on the same vehicle.

Tyres that are under or over inflated

An under-inflated tyre is a common problem that most drivers will encounter at some point. Tyres that are under-inflated make your vehicle harder to handle as they are less responsive to directional changes. This is a particular concern when driving around bends or travelling at high speed. If your tyres are over-inflated, this is also a problem. Tyres with too much pressure won’t grip the road as well as they ought to which could lead to skidding, or even spinning, when braking.

Using the wrong tyres for your vehicle

It is illegal to use tyres that aren’t suitable for your vehicle and the way in which you use it. This includes using tyres that aren’t able to support the load requirements of your vehicle, or tyres that have a maximum speed rating that you know you will exceed. Another example would be using tyres that are too big or too small for your vehicle.

What are the penalties for driving with illegal tyres?

UK drivers face severe consequences if their tyres are found to be illegal. If your tyres don’t comply with regulations, you could face a fine of up to £2,500 along with three penalty points for each illegal tyre.

What can I do to ensure that my tyres are safe?

If you notice that your tyres are worn or damaged, or you have other concerns about them, you should get them checked by an expert as soon as possible. John Delany Motors is the largest independent MOT garage in Stockport. We have over 40 years of experience in all aspects of vehicle care and maintenance and offer a wide range of services, from repairs and vehicle diagnostics to servicing and MOTs. You can read about our tyre services in Stockport here on our website. Alternatively, contact our friendly team today to find out more.