Your tyres play a crucial role in passing your MOT — especially the sidewalls. Cracks, bulges, or cuts can all raise red flags during testing and even lead to an instant fail. In this guide, we explain how tyre sidewall damage affects MOT results, which issues can be fixed before the test, and how to avoid costly replacements with simple checks.
The annual MOT in the UK is a form of vehicle testing, through which each vehicle is tested in various ways once every year. Driving without a valid MOT certificate is considered illegal.
The aim of the MOT is to test the safety of the vehicle, including its lights, brakes, and tyres – with vehicles needing to pass all areas of the test to achieve an overall pass certificate.
What Happens During an MOT?
During an MOT test, the vehicle is checked in and then attached to a series of monitors which test its working components. The brakes, lights, and tyres are all thoroughly checked, as well as fluid levels, airbags, steering and clutch, and more.
If an MOT passes all the major tests but exhibits some minor issues, a pass certificate will be issued alongside recommendations and things that the vehicle owner should do ahead of the next test.
If an MOT flags a major issue, the vehicle will fail, and it will need to be re-tested once work has been done to rectify the problems. Keep reading for some of the tyre-specific issues that can cause a vehicle to fail its MOT.
Common Tyre Sidewall Issues Flagged in an MOT
If a vehicle fails its MOT on a tyre fault, the good news is that this can often be resolved quickly and easily, by fitting replacement tyres to the vehicle.
Of course, all good news is matched with some bad news – in this case, the fact that replacement tyres can be expensive to buy, especially when you’re not expecting the outgoing.
Some of the issues that may cause your vehicle to fail due to the tyres, in particular the tyre sidewalls, include:
- Bulging that’s visible on the sidewall of the tyre
- Cuts and splits on the sidewall of the tyre – NOTE: If these are very minor, they could simply be an advisory note on your MOT, rather than a cause for failure
- If the DOT on the sidewall of the tyre indicates that it was manufactured prior to 2000
Some other issues that could connect your tyres to an MOT fail include an overly worn tread depth, poor condition of the tyre, a faulty pressure monitoring system, and having the wrong tyres fitted in terms of size and load / speed rating.
