What makes your tyres illegal?

26^th September 2023

There are specific requirements a tyre must meet to be considered legal and roadworthy in the UK. If these conditions aren?t met, your tyres will be seen as illegal. But what makes a tyre illegal? Read our guide to find out all you need to know about illegal tyres.

What are the common types of illegal tyres?

The common types of illegal tyres include:

Bald tyres
Damaged tyres
Bulged tyres

What are the legal tyre requirements?

There are several reasons why your tyres may be classed as illegal. From tyre pressure to tread depth, all of these factors contribute to the safety of your vehicle. This detailed list helps to explain what makes your tyres illegal and how you can avoid any unwanted penalties:

Size

Different vehicles require different tyres. So, it?s important that you have the correct tyre size fitted to your car to prevent endangering yourself and other drivers. It is easy to identify the right tyre size for your vehicle by simply checking your vehicle manual.

Tyre types

You cannot legally mix tyre sizes, tread patterns or tread depths. So, you must check that your new tyres are compatible with the tyres already fitted to your vehicle. Otherwise, your vehicle can become imbalanced, unsafe, and illegal to drive.

Tyre wear and condition

Often, your tyres can become damaged without you even noticing. However, worn and damaged tyres are illegal to drive on. We recommend keeping an eye out for the following signs:

Visible lumps or bulges
Cracking
Cuts
Tears across the sectional width of the tyre
Exposed ply or cord

Tyre pressure

Over or underinflated tyres can also be considered illegal, and cause uneven tyre wear. You should always inflate your tyres according to the manufacturer's specifications, which you can find in your vehicle manual.

Maintaining your tyre pressure will also help keep your running costs to an absolute minimum. Here's why:

Low tyre pressure will increase your resistance on the road, increasing your fuel consumption and reducing your handling.
Overinflated tyres can contribute to reduced braking, stability, and cornering. In extreme cases, it can even cause blowouts, which are both dangerous and costly.

How often should you check your tyre pressure?

It's recommended that you check your tyre pressure at least once a month. However, if you have a longer journey ahead of you, we recommend checking your tyre pressure before you set off and then adjust if necessary. Also, remember to check your tyre pressure when your tyres are cold, driving heats your tyres and checking them immediately after a drive will affect the tyre pressure reading. The ideal time to check your tyres after driving is by either:

Waiting a minimum of 2 hours after driving your car

Measuring your tyre pressure if you have covered no more than 2 miles

If you notice your tyre pressure falling quite drastically or have any concerns about your tyre pressure, you may have a puncture or damage to your tyre, making your vehicle unsafe - and in some instances, illegal to drive.

Tread Depth

How much tread depth should a tyre have?

The tread depth of your tyres must meet the legal minimum measurement of 1.6mm. Your tyres must not fall below this legal limit as it is against the law. We recommend replacing them at 3mm for improved safety and added peace of mind that your tyres are in a legal condition.

What are tread depth indicators?

Some tyres have tread depth indicators that help identify when the tread is running low. These are raised blocks between the grooves in the tyre tread and identify when a tyre has reached the legal tread depth.

If your tyres don't have indicators, the simplest way to check the tread depth on your tyres is to use the 20p test. Place a 20-pence piece into the grooves on the inner ¾ of the tyre - the part that is in contact with the road. If the rim of the 20p is visible, it's time to have your tyres checked by a professional.

What are the consequences of driving with illegal tyres?

Did you know that if you drive on damaged or worn tyres, you risk gaining points on your licence and being fined. The exact amount of points and the amount you could be fined can vary on the offence. You may also invalidate your insurance policy and endanger other drivers.

Visit us at one of our branches

If your tread depth has neared or is below the legal tyre limit, we offer a fantastic range of tyres for all budgets to help you get back on the road in no time. Simply search and buy tyres online or book a visit to one our centres. Alternatively, contact a member of our specialist team today.

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