A study of millions of British vehicles has found that electric cars become more reliable than petrol cars exactly where used-car folklore says they become riskiest: at high mileage.

New AutoMotive, an independent UK transport research organization, carried out the report. The company analyzed a large set of MOT tests – British for technical check-up – completed in Great Britain between July 2024 and the same month of 2026. The result is an impressive database of at least 863 million records involving 141.4 million vehicles.

Worse at first

On the raw numbers, the study looks like ammunition for the skeptics. Battery-electric cars failed 13.5% of tests, compared with 21.4% for petrol and 24.1% for diesel. That comparison should be read against fleet composition: the average petrol car turning up for its MOT is much older, at 10.4 years, while the average electric car is just 4.6. 

If you look at age alone, things seem to get worse for electric cars. Between three and twelve years old, battery-powered cars fail 1.6 to 2.3 percentage points more often than petrol cars. This is also the table that has circulated for years as proof of electric unreliability.

However, these numbers actually measure how hard the cars have worked. By their first MOT at age three, electric cars had covered a median 43,600 kilometers, a third more than the 32.990 kilomerrs of comparable petrol cars.

The reason for this higher mileage is that most early EVs were used as company cars, lease vehicles, and private-hire taxis. 

A different picture

But when the researchers checked for age and mileage simultaneously, a different picture appeared.

At low mileage, 20,000 to 40,000 miles (32.187 to 64.374 km), drivetrains are statistically indistinguishable: 12.0% of EVs failed against 11.7% of petrol cars. But from that threshold, things start to change. 

Among three-to-eight-year-old cars, EVs in the 90,000 to 120,000-mile band (144.841 to 193.121 km) failed at 16.5%, compared with 22.1% for petrol and 21.2% for diesel. Interestingly, the numbers across fuel types don’t differ much, while diesel is notoriously heavier to maintain.

Emissions hardware starts to fail

Above 193,000 km (120,000 miles), the gap widens to 16.0 versus 23.5%. So, EV failure rates stop rising; petrol and diesel rates keep compounding as engines, exhausts, and emissions hardware wear out. The latter is the fastest-growing failure category on old combustion cars, and the technology simply does not exist on EVs.

One noticeable footnote: hybrids beat both, failing just 13.6% in the 90,000-to-120,000-mile band. The most durable drivetrain on public roads is currently neither pure electric nor pure combustion.

Within the family

To strip out brand effects, the researchers also compared nine model families sold with both powertrains. Electric versions won five comparisons, tied three and lost one. The latter was the VW e-Golf, penalized by tire wear on a chassis never designed for 300 kilos of batteries.

The Hyundai Kona is the cleanest case study: 36,000 electric and 35,000 petrol cars, statistically indistinguishable below 40,000 miles (64.374 km). Above 80,000 miles, the petrol Kona fails at 17.8%, the Kona Electric at 13.0%. Electric vans outperform diesel too: at over 90,000 miles (144.841 kilometers) of commercial duty, the Nissan e-NV200 failed 29.2% of tests, compared with 33.4% for the diesel NV200.

The catches

However, the durability advantage comes with catches. EVs generate roughly 1.8 times as many tire defects as petrol cars. Interestingly, it depends almost entirely on engineering: converted combustion platforms such as the e-NV200 and the aforementioned e-Golf suffer several times the excess tire wear of purpose-built EVs like the BMW i3 or Kia Niro.

Brakes show a genuine paradox. Regenerative braking spares the friction hardware spectacularly – 2.2 brake defects per 100 tests (above 90,000 miles) versus 6.5 for petrol. But discs that are never used hard corrode: after ten years, EV brake defect rates exceed those of petrol cars. The report advises electric drivers to occasionally use the friction brakes.

Another ‘famous’ claim is that battery weight destroys suspensions. But the study debunks that: across every mileage band, EVs record fewer suspension defects than petrol cars.

Hope for the used car market

The real blind spot is battery state of health (SoH), which the study doesn’t assess. But plenty of independent surveys show degradation is more a perception problem than a reality. Even after serious mileage and frequent fast charging, the packs hold up well above the legal limit of 72% in eight years.

For the used car market, where EVs suffer strong depreciation because of a lack of trust in battery longevity, these findings matter. Mileage is one of the first things people look at when buying a used car, and these data show that a high odometer reading is far from a disadvantage in an EV. At least mechanically.