New MOT rules on Diesel cars

More stringent emissions tests have been brought in this year for all diesel cars resulting in more vehicles failing their MOTs, in addition to this all cars being tested form May onwards will now be classed in three categories; Dangerous, Major and Minor. All cars being classed as Major or Dangerous will automatically fail, anything falling into the Minor category will still pass however, the faults will be recorded.

All vehicles fitted with a diesel particulate filter or DPF which appears to have been either removed or tempered with will be an automatic fail, unless there is evidence it has been done in the process of cleaning the filters.

Neil Barlow, head of MOT policy for the Driver and Vehicles Standards Agency told Auto Express the new rules will "help motorists do the right thing".

He added: "We're changing the wording on the certificate. We've done a lot of research with motorists to find out what sort of information helps."

Any cars fitted with diesel particulate emitting "visible smoke of any colour" during tests will get a Major fault and automatically failing.

Under the new criteria, steering will be more closely scrutinised also.

A steering box leaking oil would get a Minor fault but if the oil was dripping significantly it would be pushed up to Major and fail.

The new rules came into force on May 20, 2018.