MOT tyre failure reasons
Wednesday 19th February 2020
Tyres are a common reason why your vehicle can fail its annual MOT test. Whether it’s having a faulty tyre pressure monitoring system (TMPS), not having the correct tyres for your vehicle or your tyres not meeting the legal tyre tread depth, knowing tyre-related MOT test failure points to look out for, could prevent you from forking out unnecessarily when it comes to the MOT test day!
Can tyres fail MOTs?
Yes – vehicles can fail their MOTs due to problems with their tyres. This can be due to a number of reasons, and tyres may just be part of the problem – however, we’ve listed some of the most common tyre-related MOT test failures that you can look out for ahead of your annual test.
Tyre tread depth
Uneven or abnormal tyre wear is a common MOT failure. The tread on your tyres are grooves created in the rubber, designed to remove water from the contact between the tyre and the road. If these grooves have worn down abnormally or unevenly, the tyre traction (grip) can be compromised – meaning they may have worn down to a level that is deemed as dangerous and in some cases, illegal. Without sufficient grip, your braking, accelerating and steering can all be affected, and the safety and reliability of the tyres will be affected.
That’s why there is a legal minimum tyre tread depth set out by UK law, which is 1.6mm in a continuous band around the central three quarters of the tyre. If your tyres do not abide by this depth, they will be classed as illegal, which will cause your vehicle to fail its MOT test.
The condition of the tyre
The sidewall of the tyre is the part which absorbs the pressure and assists in the car remaining stable. However, any cuts, bulges, tears or cracks in the sidewall can be a sign of serious tyre damage – and will be a reason for your vehicle to fail its MOT test without exception. Having intact sidewalls is essential for the safety of the driver and passengers alike, so having any tyre damage can compromise the safety of the vehicle entirely. Signs of tyre damage to look out for include:
- Lumps and bulges
- Visible signs of the ply and cord
- Cuts, punctures or tears
Ways to avoid tyre damage can include avoiding driving over potholes and across kerbs, and by maintaining the correct tyre pressure at all times.
Faulty tyre pressure monitoring system (TPMS)
The tyre pressure monitoring system, or TMPS, on a vehicle, uses sensors to measure tyre pressure. This technology is commonly found in most modern vehicles – and will alert the driver via a light on the dashboard when the tyre pressure needs to be changed or checked.
However, as part of your MOT, your TPMS will be checked - meaning that if your system is found to be faulty, this will result in a test failure. Checking your TMPS is not necessarily something you can check yourself manually – however, you can have this checked before your MOT during your vehicle service or reset whenever you change your tyres by a specialist tyre technician. Find out more information on how tyre pressure sensors work from our detailed guide.
Do you have the right tyres fitted?
If your vehicle is found to be fitted with the wrong tyres, this can also result in an MOT test fail. There’s several ways tyres can be found to be incorrectly fitted and combining any of the following aspects can not only lead to a fail, but also compromise the safety of your entire vehicle:
- Mixing sizes
- Mixing brands
- Different tyres on the same axle
- Seasonal tyres fitted at the wrong time of year
- Incorrect front and rear tyre pairs
This guide on ‘Can I have different tyres on my vehicle’ explains in more detail the importance of having the right tyres for your car. If you’re not sure if your tyres are of the same size, structure or are fitted correctly, our trained specialists at your local Formula One Autocentre can help.
Also, it’s important to remember that your spare tyre will be checked during your MOT test, too!