As 2018 is well underway, there are new MOT Test changes that will be introduced in May which could affect your vehicle. The MOT test is getting ready for some major changes as there are new rules for diesel cars and new categories for defects.

What are the MOT Test Changes?

When you go for an MOT test, there is always the anticipation of whether your car is going to pass or not. As the mechanic comes out to tell you your fate you stand in dear hope! Well, vehicles will now be put under more test as new rules for MOT test come into play later this year.

MOT test faults will be now put into three different classifications such as Minor, Major and Dangerous. If your vehicle is under a Major or Dangerous category, you will receive an automatic fail. Cars that have minor defects are more likely to pass, much like your advisories are logged on your MOT certificate and online so will your category rating.

Diesel cars will also experience a difference in their MOT tests. Any diesel vehicle that has a DPF (diesel particulate filter) that emits any visible colour of smoke will receive an automatic fail. This can be detected through testing such as metered tests. A mechanic will also be able to detect whether the owner of the vehicle has tampered with DPFs, they also have the right to refuse to carry out an MOT where the DPF has clearly been cut out and rewelded. The only reason you will get away with changing a DPFs is if you have legitimate reason and proof that it needed a filter cleaning.

Car Headlights

What is Minor, Major and Dangerous?

A Minor fault is one that you need to be made aware of and is more of an advisory. Something you should watch and if you feel is deteriorating over time should get checked by car maintenance in Milton Keynes..

A Major fault is one where the mechanic believes the car to have a fault that needs to be fixed there and then. If your car receives a major fault, you will not be able to take it away as it will receive an instant fail. An example of this is say your steering box was to leak a bit of oil; it would receive only a minor fault. However, if the oil is leaking a considerable amount to the point it is now dripping you will receive a major fault.

If you had a fault with your car that would put you in immediate danger, then this would constitute as a dangerous fault also failing your MOT. This will be flagged by the vehicle owner with a matter of urgency and require immediate fixing. Dangerous faults have been introduced as it is a criminal offence to drive your vehicle in a dangerous condition.

How will the changes affect you?

If you have a diesel vehicle, do not panic, if you have purchased your vehicle second hand we recommend checking you have a DPF. If it has been tampered with ensuring you have proof of why this will need to be shown to the mechanic that carries out your MOT.

Like any MOT test, there are a few checks you should be making before you take your vehicle for any test. These include blown light bulbs, windscreen wipers that are damaged or have rubber parts worn away and finally tyres with too little treat. The legal minimum of your tyre tread is 1.6mm, during the winter months, it is always recommended that you have your tyres at 3mm. These three faults account for a significant 50% of UK MOT test failures. They are all simple fixes you can make at home before your MOT test. You can get a variety of different windscreen wipers for a range of models and makes at Windscreen Wipers Direct.

Car Tyres

Most common MOT failures

We have previously mentioned the three main test failures in the UK. However, there are a few more that have become more common over the years.

Brake lights

People often forget to test their brake lights regularly as it’s not something you can physically see yourself. However, if your brake lights are not working at all this can be extremely dangerous for anyone driving behind you, it is also dangerous if your brake lights are continuously on. If you have been caught with your brake lights, either way, you can result in the police pulling you over for dangerous driving.

The best way to test your brakes is to reverse up to a wall or have someone walk around your vehicle while you gentle push on the brake pedal.

Headlights and indicators

Many people fail test for dimmed lights or indicators; these are simple things you can test at home. Have someone walk around the car while you indicate and flash your full beams. Most modern cars show when a light bulb has gone, and they are relatively cheap to replace. CarParts4Less have a range of bulbs for most vehicle makes and models.

Fuel caps

Many people don’t know that their fuel caps are tested during an MOT test. If it is not safe nor secure, you could fail your MOT. You can also fail your MOT if your car does not have enough petrol in it for the mechanic to carry out the right tests. Always ensure you have at least half a tank of petrol or diesel in the vehicle when carrying out an MOT they do not use a significant amount of fuel.


Make sure that if your MOT Test is after May 2018, you are aware of all the recent changes and know what to do before going for your MOT Test. If you want to pass your test, we recommend also taking your car for an annual car service centre, this will help indicate whether there are any potential issues.

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