A key part of passing your MOT involves assessing the condition of your tyres. In 2020, the DVSA noted that tyre issues were the fourth most common reason for failing an MOT the first time around – whether that be due to tread depth or overall condition.
The good news is that failure due to tyres is easily avoidable by performing some quick visual checks to make sure your tyres will pass an MOT. This page will cover the main rules enabling you to check your tyres before your next MOT.
A primary groove must have a tread depth of 1.6mm. Some grooves sometimes called secondary grooves may by design be shallower. These can be identified if they do not have a tread wear indicator in them. The legal tread depth limit for tyres in the UK is 1.6mm – anything below this will result in MOT failure and possibly a hefty fine and points on your license if stopped by the police. Having plenty of tread left on your tyre is essential for grip, traction and aquaplaning resistance – which is why you should be regularly checking tread depth to ensure you change your tyres before reaching the legal limit.
You can check your tread depth quickly and easily via the tread wear bars visible on your tyres or using a depth gauge. You can also use a 20p coin to check the tread – to learn more read our guide to checking your tyre treads.
You should always have matching tyre structures (radial or crossply) on the same axle and ideally on each wheel. If your tyres do not match on a single structure it will lead to an MOT failure as this can be dangerous leading to unpredictable braking and handling. This does not apply to patterns - other tyres of construction including Run On Flat, load and speed can be mixed in the UK but this is strongly advised against.
Damage to your tyre sidewall such as a lump, bulge or tear caused by separation or partial failure risks overall tyre failure or a serious accident and could fail an MOT. Small cuts not deep enough to expose carcase may not be a failure. Some cuts and splits may however still have an advisory. It is recommended to carry out visual checks on the condition of your tyres regularly and to replace any tyres that have damage to the sidewall as soon as possible to maintain safety and vehicle handling and performance.
As well as sidewall damage, if there is significant damage to the tread cap or tyre shoulders that expose the cords or ply, it will lead to failing your vehicle’s MOT. As per tyre sidewall damage above, any tyre with exposed cords or ply should be replaced immediately.
Under-inflated tyres will fail an MOT test as this can impact on the way a vehicle handles and performs which can prove to be dangerous. As tyres will naturally lose pressure over time, it’s important to carry out regular checks – not only before your MOT – to keep pressures at those recommended by the vehicle manufacturer. Although these are not physcially checked as part of your MOT test, any tyre that is visibly under inflated can lead to a fail.
If your car has a TPMS it will be checked as part of your MOT and will result in failure if it is working incorrectly or not at all. This is something you should include in regular servicing o prevent MOT failure through a faulty battery or corroded sensor stem.
The above points cover some of the most common reasons for failing your MOT due to tyres, but there are additional, less common reasons your tyres may fail an MOT – such as having different tyres on the same axle or load capacity not meeting the minimum requirement for your vehicle. For more information you can visit the MOT Inspection Manual.
You can increase the chance of passing your MOT and help to prolong the life of your tyres by conducting regular maintenance and checks on your tyres throughout the year. This involves ensuring optimal tyre pressure, checking your tread depth, ensuring wheels are aligned and avoiding bad driver habits or overloading your vehicle.
Spare tyres are not checked as part of an MOT – only tyres that are fitted to the vehicle at the time of MOT are checked. This is because not all vehicles need or have a spare tyre – for example vehicles with Run On Flat tyres or temporary repair kit do not require a spare.
There is currently no guidance around tyre age in order to pass MOT tests for private passenger vehicles.
You should be using tyres that are the correct size for your vehicle, with the correct speed and load rating. Load index is only failed if inspector has reason to believe it is not to the requirement. Speed ratings are not failed as long as tyre has a capability of speeds up to 70mph. Your vehicle could fail an MOT test using the wrong tyres.