What Makes Your Tyres Illegal?

26^th September 2023

Driving on illegal tyres is not just unsafe - it’s against the law in the UK. Tyres that fail to meet the legal requirements can lead to fines, penalty points on your licence and can even invalidate your car insurance. But what makes tyres illegal? This helpful guide by our experts at The Tyre Group explains everything you need to know, helping you stay compliant and safe on the road.

Common Types of Illegal Tyres

Illegal tyres are those that fail to meet road safety standards. The most common types include:

Bald Tyres: Tyres with insufficient tread depth.
Damaged Tyres: Tyres showing cracks, cuts, or exposed cords.
Bulged Tyres: Tyres with lumps or bulges due to internal damage.

What Are the Legal Tyre Requirements in the UK?

UK tyre laws are clear about the standards tyres must meet to be considered roadworthy. Below we have established the key factors that can make your tyres illegal.

1. Tyre Size and Compatibility

Every vehicle has a recommended tyre size that is specified in the vehicle manual. Fitting the wrong size or mixing different tyre types, such as tread patterns or depths, is illegal. It can lead to imbalance, reduced grip and poor handling, making your vehicle unsafe to drive.

2. Tyre Wear and Condition

Tyres must be in good condition to remain roadworthy. Illegal tyre damage includes:

Visible lumps or bulges.
Cracks or cuts.
Tears across the tyre width.
Exposed ply or cords.

If you notice these signs, your tyres will be unsafe and illegal.

3. Tyre Pressure

Incorrect tyre pressure, whether over or underinflated, can render your tyres illegal, to find out what the correct tyre pressure should be for your vehicle, check the vehicle's handbook, or look on the inside of the driver's door for a tyre pressure label. It also affects your vehicle’s performance:

Low pressure: Increases fuel consumption and uneven wear.
High pressure: Reduces braking efficiency and stability, increasing the risk of blowouts.

How Often Should You Check Tyre Pressure?

Check tyre pressure at least once a month or before long journeys. Ensure you measure it when the tyres are cold:

Wait two hours after driving.
If you must check after driving, ensure the trip is under two miles.

If you notice rapid pressure loss, this could indicate a puncture or damage, making your tyres illegal. Come and see us at your local Tyre Group branch for new tyres.

4. Tread Depth

What Is the Legal Tread Depth for Tyres in the UK?

UK law requires a minimum tread depth of 1.6mm across the central three-quarters of the tyre and around the entire circumference. Driving with tyres below this limit is illegal.

Why Replace Tyres Before Reaching 1.6mm?

For added safety, many experts recommend replacing tyres at 3mm tread depth, as this provides better grip and braking performance, especially in wet conditions. Speak to our specialists at The Tyre Group if you need a second opinion on your tyres tread depth.

How to Check Your Tread Depth

Use the 20p Test: Insert a 20-pence coin into the tread groove. If the rim of the coin is visible, your tread is below the legal limit, and you should replace the tyre immediately.
Look for Tread Depth Indicators: Some tyres have raised blocks in the grooves to indicate when the tread has worn down to the legal limit.

Consequences of Driving on Illegal Tyres

Driving on illegal tyres can have serious legal and financial consequences:

Fines: Up to £2,500 per tyre.
Penalty Points: Up to three points per illegal tyre.
Insurance Risks: Your insurance policy may be invalidated if your vehicle has illegal tyres.

More importantly, illegal tyres increase the risk of accidents, endangering you and other road users.

How to Avoid Illegal Tyres

Staying on top of tyre maintenance is key to avoiding penalties and staying safe. Here’s a quick checklist covered in this helpful guide.

Check your tread depth monthly using the 20p test.
Inspect tyres for visible damage such as cuts, bulges, or cracks.
Maintain the correct tyre pressure as per the manufacturer’s guidelines.
Replace tyres if they approach 3mm tread depth to ensure optimal performance.

Need New Tyres? Visit Us Today

If your tyres don’t meet the legal requirements, don’t delay, replace them today! We offer a wide range of tyres to suit all budgets, ensuring your vehicle stays roadworthy and safe.

Search and Buy Online: Browse our tyre selection online.
Book an Appointment: Visit your local branch for professional advice and fitting.

For more information or expert guidance, contact our specialist team today.

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