The RAC has warned motorists could be confused by the new MOT categories, which grade defects into minor, major or dangerous.

The changes, as part of a new EU directive, affects cars, vans and motorbikes in England, Scotland and Wales but there’s a different MOT system in Northern Ireland.

From 20 May, cars tested that have dangerous and major defects will automatically fail the MOT. A car with a minor defect can still be driven on the road, although the information will need to be noted on the MOT certificate, which will also see a new design.

There will also be stricter rules on diesel car emissions. In particular, cars with a diesel particulate filter (DPF which captures and stores exhaust soot to reduce emissions) will face stricter limits.

You’ll receive a major fault if the MOT tester can see smoke of any colour coming from the exhaust or if they find evidence that the DPF has been tampered with.

There are also changes to what’s included in the MOT:

• if tyres are obviously underinflated
• if the brake fluid has been contaminated
• for fluid leaks posing an environmental risk
• brake pad warning lights and if brake pads or discs are missing
• reversing lights on vehicles first used from 1 September 2009
• headlight washers on vehicles first used from 1 September 2009 (if they have them)
• daytime running lights on vehicles first used from 1 March 2018 (most of these vehicles will have their first MOT in 2021)

Lastly, if you’ve a car which is 40 years or older (from when it was first registered), then it won’t need to undergo an MOT as long as it’s not been substantially changed, such as having a new engine installed. Currently only vehicles first built before 1960 are exempt from MOTs.

Consider booking an MOT this week

You can get an MOT up to a month (minus a day) before it runs out though you will still keep the same renewal date.

As an example, if your MOT runs out on 15 May, the earliest you could have presented it was on 16 April. You can get an MOT earlier, but the MOT renewal date for the following year will be different.

If your MOT is due soon and you’re concerned your car may not pass as easily under the new system, check with your local garage to see if you can get it booked in before Sunday.

The Driver and Vehicle Standards Agency (DVSA) confirmed that as the changes come into effect from 20 May, MOTs that take place before then won’t come under the new system. Further, there’s no change to the cost of an MOT – the maximum you can be charged for a car is £54.85.

Confusion over categories

RAC spokesman, Simon Williams, said: “We fear many motorists could end up being confused by the new categories which give an indication as to the seriousness of vehicle defects identified in an MOT test.

“Rather than MOT failures simply being black and white, 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.”

If you’re caught driving without a valid MOT, you face a £1,000 fine. But drivers can now sign up to the government’s free MOT reminder service to receive a text or email when their car’s due for an MOT.