High-mileage EVs are more durable than petrol cars, major MOT study claims

High-mileage electric cars are less likely to fail an MOT than petrol cars of the same age and mileage, new data claims.Analysis of 47.4million MOT tests has found that, at 60,000 miles, electric cars are more durable than petrol cars.The study, commissioned by the British Vehicle Rental and Leasing Association (BVRLA) and carried out by independent transport research organisation New AutoMotive, analysed official DVSA MOT records to examine what happens to electric cars as they age and accumulate mileage.While relatively little difference between electric and petrol cars at lower mileages was found, from 60,000 miles the pattern changes markedly.Rather than continuing to deteriorate as mileage increases, the MOT failure rate for electric cars levels off at approximately 16 per cent, while petrol and diesel failure rates continue climbing.By the time cars have clocked over 120,000 miles, the EV MOT failure rate remains on a 16 per cent plateau, compared to 23.5 per cent for petrol cars.However, experts point out that there is a hole in EV MOT testing where batteries are not measured in terms of health or remaining capacity, as we explain below... Motor magic: Analysis of 47.4m MOT tests has found that, at 60,000 miles, electric cars are more durable than petrol carsWhen do EVs start being more durable than petrol cars?There's little in it when you look at electric and petrol cars at lower mileages once both vehicle age and mileage are taken into account.Between 20,000 and 40,000 miles (low mileage), 12 per cent of battery-electric vehicles failed their MOT compared with 11.7 per cent of petrol cars.The plateau then kicks in at around 60,000 miles, beyond which EV failure rates level off at approximately 16 per cent.At the high mileage point (90,000-120,000 miles), and among three-to-eight-year-old vehicles, EVs fail at 16.5 per cent, compared to 22.1 per cent for petrol and 21.2 per cent for diesel – a 25 per cent relative durability advantage.Once extreme mileage (120,000+ miles) is reached, the durability gap widens to 7.5 percentage points (16 per cent failure rate for EVs v 23.5 per cent for petrol).An MOT test checks everything important – from lamps to brakes, steering, and wiring, to name just a few – to ensure the vehicle meets legal roadworthiness standards in the UK.Cars must go in for an MOT test once a year after reaching three years of age. This is the same for EVs.Toby Poston, chief executive of the BVRLA, said: 'Mileage has always been one of the first things people look at when buying a used car, and passing 60,000 or 70,000 miles can have a big impact on how a vehicle is perceived. 'This research suggests we need to think differently when it comes to electric vehicles.'Many of the EVs now entering the used market have had their first life in company and leasing fleets and have already covered substantial mileage. 'What this data shows is that mileage alone should not put consumers off. A well-maintained, higher-mileage electric car can be an extremely durable used vehicle.'That matters because the used market is where the transition to electric becomes accessible to millions more motorists. 'Giving buyers confidence in these cars will be critical to creating a healthy and affordable second-hand EV market.'Hybrid cars also performed strongly in the analysis and in several categories recorded lower MOT failure rates than either petrol cars or fully electric models.For instance, the fail rate for hybrids was 11.8 per cent (total tests in 12 months) compared to 13.5 per cent for fully electric vehicles and 21.4 per cent for petrol.The researchers stress the study is not intended to establish one powertrain as universally more reliable than another, but to test concerns about whether battery-electric vehicles become less roadworthy as they age and accumulate mileage. Once extreme mileage (120,000+ miles) takes place, the durability gap widens to 7.5 percentage points (165 failure rate for EVs v 23.5% for petrol)EVs stay on the road for longerThrough longitudinal cohort tracking of vehicles over consecutive test years, the study also found that electric vehicles stay on the road at double the rate of combustion vehicles.Tracking whether vehicles returned for a subsequent MOT within 30 months found that at age 15, 94.6 per cent of electric cars returned compared with 88.1 per cent of petrol cars.That equates to an implied road-exit rate of 5.4 per cent for electric cars compared with 11.9 per cent for petrol.Road exit can include vehicles being scrapped, exported or declared Statutory Off-Road Notification, so the study does not claim that all vehicles which disappear from the MOT dataset have been scrapped.Nor does the longevity appear to be explained by old EVs becoming low-mileage second cars.Electric vehicles recorded higher median annual mileage than petrol cars at every age examined between four and 16 years. At age 12, for example, electric cars covered a median of approximately 4,920 miles a year compared with 4,410 miles for petrol cars.EVs do perform worse in some categoriesThe study also identified areas where electric cars performed worse, the most glaring being tyres.Across the dataset, EVs recorded approximately 1.8 times as many tyre defects as petrol cars, although the analysis found that the problem was particularly pronounced among some earlier EVs adapted from combustion-engine platforms.Regenerative braking also produces a more complicated picture.High-mileage EVs experienced substantially fewer brake defects, but older, low-mileage electric cars showed increased friction-brake defects. This was attributed to corrosion associated with the physical brakes being used less frequently.Batteries aren't checked during an MOTAs battery health remains an issue with used EVs, the research has pointed to the hole in MOT testing where batteries are not measured in terms of health or remaining capacity.MOT tests do not measure battery state of health, electrochemical degradation or charging performance.The researchers say battery-health information should therefore be considered alongside mechanical roadworthiness when assessing an individual used EV.Poston adds: 'This isn't an argument for buying a used EV without doing your homework. 'Buyers should look at its history, condition, tyres and battery health just as they would scrutinise the engine, gearbox and service history of a petrol or diesel car.'