May will see a major overhaul in MOT testing and here is how it will affect you and how your car is judged.

The MOT test is getting a major revision on May 20, which will bring in tougher measures against diesel car through new defect categories.

Faults will now be classified as Dangerous, Major and Minor, if classed as Dangerous or Major it will be an instant fail for your vehicle.

The crackdown on diesel car emissions will see cars failing their MOT if the car is putting out any smoke whatsoever.

Testers are also being told to do thorough checks of a car's DPF (Diesel Particulate Filter) to ensure they haven't been tampered with or removed.

Some diesel drivers remove the filter to boost performance and increase miles-per-gallon.

It means that if a car was fitted with a DPF as standard, its removal would mean an instant MOT fail.

Testers are also asked to check whether or not brake discs are worn or corroded, while they must also ensure that they are properly attached to the wheel hubs too.

There have been calls for the Government to simplify the way the MOT test is conducted, with RAC spokesperson Simon Williams saying: "The new system creates the potential for confusion as testers will have to make a judgement as to whether faults are 'Dangerous', 'Major' or 'Minor'.

“This will surely be open to interpretation which may lead to greater inconsistency from one test centre to another.

“Motorists may also struggle to understand the difference between 'Dangerous' and 'Major' failures. The current system ensures that any vehicle with a fault that doesn't meet the MOT requirements is repaired appropriately before being allowed back on the road."