A landmark analysis of more than 45 million Ministry of Transport (MOT) test records has provided a definitive look at the long-term reliability of electric vehicles, suggesting that battery-powered cars are significantly more durable than their internal combustion engine counterparts as they age. The research, conducted by the prominent data and policy organization New AutoMotive, indicates that while the difference in reliability between petrol and electric cars is negligible during their early years, a dramatic divergence occurs once vehicles surpass the 120,000-mile mark. According to the findings, high-mileage electric vehicles are approximately 25% less likely to fail their MOT than petrol equivalents, challenging long-standing skepticism regarding the longevity of electric drivetrains.
The study represents one of the most exhaustive deep dives into the UK’s vehicle reliability data to date. By examining tens of millions of individual test results, researchers were able to track the performance of various propulsion systems across their entire lifecycles. For vehicles with low mileage, the data showed almost no distinction in roadworthiness. At the lower end of the odometer, the difference in MOT failure rates between petrol and electric cars was recorded at a mere 0.3%. This suggests that for the average driver who changes their vehicle every few years, the choice of fuel type has little impact on the likelihood of encountering a major mechanical failure that would result in an MOT rejection.
However, the narrative shifts fundamentally as vehicles enter the middle and later stages of their operational lives. The research identified a critical "pivot point" at approximately 60,000 miles. Up to this threshold, both petrol and electric vehicles follow a similar trajectory of increasing wear and tear. But as the 60,000-mile barrier is crossed, the MOT failure rate for electric cars begins to level off, stabilizing at roughly 16%. In stark contrast, the failure rates for both petrol and diesel vehicles continue to climb steadily, reflecting the mounting mechanical stresses inherent in internal combustion engines as they accumulate high mileage.
Ben Nelmes, the Chief Executive of New AutoMotive, highlighted the importance of this specific distinction in the data. He noted that previous attempts to compare the reliability of electric and traditional cars have often been skewed by the relative youth of the electric fleet. Because mass-market electric vehicles have only been available in significant numbers for a decade, a simple comparison of all EVs on the road against all petrol cars on the road would naturally favor EVs, as they are, on average, much newer. Nelmes emphasized that the methodology of this study was designed specifically to bypass that bias by isolating mileage as the primary variable.
"The important thing about this study is that we can separate age from mileage," Nelmes explained. He pointed out that looking simply at headline MOT numbers provides a misleading picture of the current state of the UK’s automotive landscape. Because electric vehicles are often used in commercial fleets or by high-mileage commuters to take advantage of lower running costs, they often cover considerably more miles in a shorter period than their petrol counterparts. By comparing cars based on how much they have actually been driven, rather than just when they were first registered, the research provides a much clearer view of mechanical resilience.
The superior performance of high-mileage electric cars is largely attributed to the relative simplicity of their powertrains. A traditional internal combustion engine consists of thousands of moving parts, including pistons, valves, fuel injectors, and complex exhaust systems, all of which are subject to heat, friction, and vibration over time. These components require precise lubrication and cooling, and as they age, the likelihood of a failure in one of these systems—such as an emissions leak, a fuel system fault, or a transmission issue—increases. Electric vehicles, by comparison, have significantly fewer moving parts. The absence of a traditional multi-speed gearbox, a complex exhaust treatment system, and the various belts and pumps associated with petrol engines appears to result in a more robust vehicle over the long term.
However, the study was not entirely a clean sweep for electric vehicles. While they excelled in overall mechanical durability and drivetrain reliability, the data highlighted specific areas where EVs are currently less durable than petrol cars. Most notably, the analysis found that across the entire dataset, electric vehicles recorded approximately 1.8 times as many tyre-related defects as petrol cars. This finding aligns with long-held observations from automotive experts regarding the unique stresses that electric cars place on their rubber.
The increased rate of tyre wear in electric vehicles is generally attributed to two primary factors: weight and torque. Because of the heavy battery packs required to provide competitive range, electric vehicles often weigh significantly more than petrol cars of a similar size. This additional mass puts greater constant pressure on the tyres. Furthermore, electric motors deliver maximum torque instantly from a standstill, which can lead to more aggressive wear during acceleration compared to the more gradual power delivery of a petrol engine. The MOT data suggests that while EV owners may save money on engine repairs, they are likely to face more frequent expenses related to tyre maintenance and replacement.
Interestingly, the study also shed light on the performance of hybrid vehicles, which utilize both an internal combustion engine and an electric motor. Despite the perceived complexity of having two separate power systems, hybrids performed exceptionally well in the analysis. In several categories, hybrid cars recorded lower MOT failure rates than both pure petrol cars and fully electric vehicles. This suggests that the hybrid market has matured to a point where the systems are highly refined, or perhaps that hybrid drivers tend to have driving patterns that are particularly conducive to maintaining vehicle health.
The implications of this research are significant for the second-hand car market. One of the primary barriers to the widespread adoption of electric vehicles has been "range anxiety" and concerns over the long-term health of the vehicle. Prospective buyers of used cars often fear that an older electric vehicle will be a liability, particularly once it is out of its manufacturer’s warranty. This data suggests the opposite may be true: for a buyer looking at a vehicle with over 100,000 miles on the clock, an electric car may actually be a safer bet in terms of passing its next roadworthiness test than a traditional petrol vehicle.
Furthermore, the stabilization of the failure rate at 16% for electric vehicles after 60,000 miles suggests a "plateau of reliability" that petrol cars do not share. For petrol and diesel vehicles, the MOT failure rate continues to track upward in a near-linear fashion as the miles pile on, reflecting the gradual degradation of the engine and its ancillary systems. The fact that EVs do not follow this trend could change how fleet managers and long-distance drivers calculate the total cost of ownership, as the later years of a vehicle’s life may not be as plagued by escalating repair costs as previously assumed.
As the UK moves toward its targets for decarbonizing transport, the longevity of the existing and future fleet remains a central concern for policymakers. If electric vehicles prove to be more durable over hundreds of thousands of miles, it could lead to a longer average lifespan for vehicles on the road, potentially reducing the environmental impact associated with manufacturing new cars. The New AutoMotive study provides a data-driven foundation for this optimism, suggesting that the transition to electric power may bring with it a new era of automotive durability.
While the tyre defect statistics remain a point of concern for the industry, the overall picture painted by the analysis of 45 million MOT tests is one of a technology that is proving its worth under real-world, high-stress conditions. As the electric fleet continues to age and more vehicles reach the high-mileage categories, researchers will be able to refine these findings further. For now, however, the data indicates that once an electric car reaches the 120,000-mile mark, it is not reaching the end of its life, but rather demonstrating a level of resilience that its petrol-powered predecessors struggle to match.
