Nearly one is seven vehicles that passed their MOT test last year should have failed, according to a new study.

Analysis of the Driver and Vehicle Standards Agency’s (DVSA’s) MOT Compliance Survey (2019 – 2020) by What Car?, found 13.58% of vehicles that passed an MOT test should have failed.

A team of DVSA vehicle examiners retested a randomly selected sample of 1,671 vehicles, which had undergone an MOT test at test stations across the UK. It disagreed with the test outcomes in 16.82% of cases.

In 70.1% of cases, the DVSA found at least one defect which the MOT test station missed or had incorrectly recorded, while the DVSA experts disagreed with three or more defects in 56.5% of vehicles.

The DVSA examiners also felt that 3.23% of failures deemed to be worthy of a pass certificate.

Safety critical features such as the brakes and suspension were subject to the biggest discrepancy between the DVSA and MOT testers. Brakes had the highest number of misdiagnosed defects, at 17.74%, followed by the suspension (14.56%), tyres (13.22%), and lights, reflectors and electrical equipment (11.51%).  

Following its investigation, the DVSA issued 24 disciplinary action recordings and 179 advisory warning letters to the vehicle test sites it visited. Between them, they were responsible for 12.1% of all vehicles re-tested by the Government agency. 

What Car? surveyed 1,425 used car buyers as part of its investigation, with 11.9% stating they knew of a local garage that has a reputation for passing cars for their MOT. For 76.8% of buyers, a prospective car’s MOT record was either ‘very important’ or ‘important’ when deciding on whether to buy.

Steve Huntingford, editor of What Car?, said: “Our investigation has shown the significant differences between the DVSA’s own testing standards and those upheld by some in the industry. This poses a serious concern, with potentially hazardous vehicles being allowed to remain on the road, putting their drivers and other road users at risk. It also complicates matters for used buyers who often rely on a vehicle’s MOT history as an indicator for a car’s safety and reliability.”