The number of cars failing MOT tests due to emissions has doubled since tighter regulations were implemented into the test earlier in the year.

Information from the Drivers & Vehicle Standards Agency (DVSA) shows that almost 750,000 cars have failed the tougher emissions test as part of the revamped MOT, which was brought in on May 20, 2018.

The figure was more than double the 350,472 cars which failed for emissions in the same period in 2017.

The stricter MOT test brought in new categorisation for failures and advisories, as well as the important crackdown on polluting vehicles. The new rules dictate cars must have lower limits for tailpipe emissions while certain diesel vehicles which produce any visible smoke receive automatic failures.

Cars can also fail a test if there is evidence that a diesel particular filter has been tampered with – these devices help to reduce emissions in these vehicles, but can be problematic on older cars, particularly if they only cover shorter journeys, which is why they are occasionally tampered with or removed altogether.

Categories such as ‘Minor’, ‘Major’ or ‘Dangerous’ are the new ways for monitoring a car’s faults. Both Dangerous and Major categorisation is equivalent to a failure (cars with Dangerous faults are illegal to drive on the road until fixed) while Minor is the equivalent to an advisory.

The DVSA has said that around 16 million vehicles have been tested so far with the new system.

The number of diesel vehicles failing the test has also shot up dramatically since the new test was brought in. Between May 20 and November 19 last year, 58,004 diesel vehicles failed due to emissions, but for 2018 this had risen to 238,971. The number of petrol cars failing tests for the same reason also increased from 292,468 to 505,721.

Gareth Llewelyn, DVSA chief executive said: “The DVSA’s priority is to protect everyone from unsafe vehicles and drivers.

We are committed to making a real difference to those in society whose lives and health are blighted by poor air quality”

Ted Welford


November 21, 2018