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Jamie Gibbs

MOT shakeup may see rise in car failures


In May this year, some major changes are happening to the MOT test. We explore these changes and what they mean to drivers.


2018 will see a lot of changes to motoring laws. 

On May 20, new changes to the MOT test could mean that it’ll be harder to pass. 

These are being implemented to meet a new EU directive, the European Union Roadworthiness package. 

The changes to the test involve a new type of emissions testing, and measuring defects within three categories. 

The new changes will apply to all vehicles, but there is debate over how effective the new test will be. 

What are the new MOT categories?

The biggest change to the MOT test is how defects will be categorised. These are ‘dangerous’, ‘major’ and ‘minor’. 

Minor defects are the same as an advisory. These are things that will eventually need fixing on your car, but will not fail your vehicle. For example, if the brake fluid is below the minimum mark. 

Major and dangerous faults will need to be dealt with before the car is deemed roadworthy and will fail the MOT.  For example, if the brake fluid is significantly below the minimum mark.

What are the changes to the MOT emissions test?

Emission testing will also be changed. The old emissions test – the New European Cycle (NEDC) - was designed in the 80s, and has come under scrutiny in recent years.

The new emissions test – The Worldwide Harmonised Light Vehicles Test Procedure (WLTP)- will be tougher on measuring fuel economy and CO2 emissions.

Supporting this will be the Real Driving Emissions test (RDE), which will measure the amount of nitrous oxide (NOx) created by the car. 

Diesel cars may struggle with this part of the test, as their emissions are higher in NOx than petrol.

To amend this, garages will have to make changes to their diesel smoke meter setting or software. The government will be working with garage equipment manufacturers to help them get ready for this. 

As of May, any diesel vehicle that has a particulate filter will fail the test if it emits smoke of any colour. Any tampering with this filter will also mean a failed MOT.

MOT test

Are older cars exempt from the MOT test? 

In 2012, it was announced that vehicles that were manufactured before 1960 will be exempt from MOT tests. 

In May it’ll be extended to vehicles that were manufactured before 1977. This is because cars of this type are usually maintained by enthusiasts, and statistically have lower accident and MOT failure rates than regular cars.

Chris Grayling, Transport Secretary says: “I can assure you that as we plan for a revolutionary future, we are not losing sight of the importance of maintaining the heritage of the motor industry”

His comments are supported by Sir Greg Knight MP, who says that the MOT test is “becoming progressively irrelevant for historic vehicles”

Are these changes a good idea? 

Previous MOTs were black and white, with the categories being ‘advisory’ or ‘fail’. The two categories meant there was little room for manoeuvre.

Now test centres will have to use their own judgement to decide whether a car is fit to pass its MOT. This could lead to inconsistencies between garages. 

The difference between ‘major’ and ‘dangerous’ faults could also be confusing for motorists. The current system classes it as a fail or pass, so having extra categories could cause some issues. 


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