Did you know that issues relating to tyres are a common reason for MOT failure?

By performing a few quick visual checks ahead of time and acting accordingly, you can ensure that your tyres will pass an MOT test. 

Read on and find out some of the key MOT rules concerning tyre health that you should bear in mind ahead of your next MOT. 


What Are The Main MOT Rules For Tyres?


Tread Depth Must Be At Least 1.6mm

A primary groove on a tyre must have a tread depth of 1.6mm, as a legal minimum.

Certain secondary grooves may be designed to be shallower - you can identify these if they do not have a tread wear indicator in them. 

Anything below this legal tyre tread limit will result in MOT failure, and could land you a hefty fine and even points on your licence if you are stopped by the police. 

When your tyres have the appropriate tread level, this will help with traction and allow your tyres to better grip the road surface, thereby reducing the risk of aquaplaning


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There Should Be No Damage To The Tyre Sidewall

Any lumps, tears or bulges in the tyre sidewall caused by separation could put the driver in danger, meaning that any serious damage to the tyre sidewall could result in MOT failure.

The tyre sidewall is designed to withstand pressure and keep your car stable, and any damage can put you at a higher risk of tyre blowout

Small cuts which do not expose the carcass may not result in MOT failure, but any cuts or splits could still result in an MOT advisory


Cords and Plys Must Not Be Exposed

Any significant damage to the tyre tread cap or tyre shoulders which exposes the cords or ply will result in MOT failure.

A tyre with exposed plys and cords should be replaced as soon as possible.


A number of tyres piled up on top of one another.

Make sure that you inspect the condition of your tyres ahead of an MOT test, and have them replaced in advance of the test if necessary. 


Tyres on The Same Axle Must Have Matching Structures

Tyres should have matching tyre structures - be it radial or crossply - if they are on the same axle. Ideally, you  should have matching tyre structures on each wheel too.

Tyres which do not match on a single structure will result in MOT failure, as this can result in unpredictable handling and braking.

Whilst Run On Flat, load and speed tyres can technically be mixed in the UK, we would advise that you do not mix tyres. 


Tyres Must Be Properly Inflated

If your tyres are under-inflated, this will cause your vehicle to fail the MOT test, as this can have an effect on how your vehicle handles and make for a dangerous driving experience.

Tyres lose pressure over time, which is why it is so important that you regularly check your tyres - not just ahead of an MOT test - and inflate them to the appropriate PSI recommended by the vehicle’s manufacturer when needed. Whilst your tyres will not be physically checked during an MOT test, a tyre which is visibly under-inflated can cause MOT failure. 

Whilst over-inflated tyres may not result in MOT failure, this can have other issues for your vehicle, so ensure that you always have your tyres properly inflated so that you can stay safe on the road.

Properly inflated tyres will wear more evenly, meaning they will be safer and more fuel efficient. 


Tyre Pressure Monitoring System (TPMS) Must Work

If your vehicle has a tyre pressure monitoring system (TPMS) then it will be checked during an MOT test, and this can lead to MOT failure if it is not working correctly. You should have your TPMS checked during regular maintenance to ensure there are no issues concerning a corroded sensor stem or a faulty battery

The TPMS uses electronic sensors in the tyres to measure tyre pressure, alerting the driver of any drops or increases in tyre pressure via a dashboard warning light.

Bear in mind that the system will need to be reset if you change your tyres, and some components such as internal batteries will need to be replaced.

You should have the system serviced when you have your tyres changed.


Tyres Must Be The Correct Size and Have The Correct Speed Rating

The tyres that you use must be the correct size for your vehicle, with the correct speed rating and load rating. Speed ratings will not result in a fail, so long as the tyre has a capability of speeds up to 70mph, but you could fail an MOT test if you use the wrong tyres

Please note that spare tyres are not checked during an MOT test, but plenty other components of your vehicle will be. 

There are currently no MOT rules surrounding tyre age for private passenger vehicles, but tyres over 10 years old at the time of the test will be failed if they are on any front steered axle, or any rear axle of a minibus with a single wheel fitment. 

Tyres will also fail the MOT test if they do not display a date code on at least one side of the tyre.

If the date code has worn away due to kerbing, for instance, then a major or minor defect may be recorded depending on the location of the tyre. 


Are There Pre-MOT Tyre Checks I Can Do Myself?

By regularly carrying out visual checks of your tyres and having damaged tyres replaced when necessary, you can ensure that your tyres are safe to drive on and that your vehicle performs and handles well. 

You can check the tread depth of your tyres using a 20p coin or a depth gauge, or by inspecting the tread wear bars on your tyres.

To avoid damage to the tyre sidewall, you should avoid driving over potholes, kerbs or sharp objects. You should also clean your tyres regularly, and ensure that your tyres are properly inflated. 

Take good care of your tyres, and you can give your vehicle the best chances of passing its next MOT test. 


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We hope that you have enjoyed learning about the MOT rules for tyres. If you would like to read more about tyres, why not find out how to take care of your tyres on a budget?