A quarter of a million cars failed their MOT tests on emissions in the six months following the changes to MOT rules deployed in May 2018. Tracking steady, that means 1.5 million emissions-related failures by May of this year.
How have emissions standards changed for an MOT?
The recent changes are described as “the most comprehensive changes to the rest regarding air quality” by vehicle data provider Glass’s. It’s predicting a record number of cars and vans being deemed beyond economic repair. Perhaps predictably, diesel cars that are feeling the worst of the heat.
Changes to the test that are causing the most failures
- Stricter emissions limits for cars with diesel particulate filters (DPFs)
- Automatic failure for cars with tampered or removed DPFs
- Automatic failure for cars fitted with DPFs with smoky exhaust gasses
That makes diesel vans four and a half times more likely to fail the new emissions elements of the MOT. The raft of failures can only go up. Diesel particulate filters are expensive and sometimes difficult to change, therefore making it difficult to justify carrying out the required work to get a diesel with a dodgy DPF through an MOT.
Tighter regulations, reduced appeal
The associated risks of buying diesel are affecting values. A year’s MOT has never been more vital to maintaining the value of your DPF-equipped diesel car.
Weariness around diesel, both in the new and secondhand market, only continues to increase, as the fuel’s overall market share contuse to dwindle.
“The latest revision in MOT rules is not the biggest change since the MOT began back in 1960 when the test only affected cars over 10 years of age,” said Jonathan Brown, car editor at Glass’s.
“However, these changes that aim to improve air quality, will impact older diesels significantly with failure rates likely to increase.”