High-Mileage EVs 25% Less Likely to Fail MOT Than Petrol Cars

High-mileage electric cars are significantly less likely to fail their MOT than comparable petrol vehicles, according to a major new analysis of 47.4 million UK MOT tests.

The research found relatively little difference between electric and petrol cars at lower mileages. But once vehicles pass around 60,000 miles, their MOT records begin to diverge.

Electric vehicle failure rates appear to level off while the proportion of petrol cars failing their MOT continues to rise as the miles accumulate.

Among cars aged between three and eight years old with 90,000 to 120,000 miles on the clock, 16.5% of electric vehicles failed their MOT compared with 22.1% of petrol cars.

That makes the high-mileage EVs around 25% less likely to fail their MOT.

And at more than 120,000 miles, the difference becomes greater still.

EV advantage appears after 60,000 miles

The research was commissioned by the British Vehicle Rental and Leasing Association (BVRLA) and carried out by independent transport research organisation New AutoMotive using official MOT data.

Importantly, the researchers took account of both vehicle age and mileage when making the main comparisons.

At lower mileages, the results provide little evidence of a significant EV advantage.

Between 20,000 and 40,000 miles, 12% of electric cars failed their MOT compared with 11.7% of petrol cars.

The interesting change happens as mileage increases.

From around 60,000 miles, EV failure rates begin to level off at roughly 16%, while failure rates among petrol cars continue climbing.

For three-to-eight-year-old vehicles covering 90,000 to 120,000 miles, the figures were:

• Electric cars – 16.5% MOT failure rate
• Petrol cars – 22.1% MOT failure rate

Above 120,000 miles, the study found:

• Electric cars – 16% MOT failure rate
• Petrol cars – 23.5% MOT failure rate

For garages, MOT testers and motorists, that is an interesting finding because high mileage has traditionally been associated with increasing wear, repair bills and roadworthiness problems.

Why could high-mileage EVs perform better?

One possible explanation is the fundamental mechanical difference between electric and combustion-powered cars.

An electric powertrain has far fewer moving components than a conventional internal combustion engine and does away with numerous components associated with petrol and diesel vehicles.

However, this needs to be treated carefully in the context of an MOT.

An MOT does not assess whether an engine, electric motor or traction battery is generally reliable. It assesses whether a vehicle meets prescribed roadworthiness and environmental requirements at the time of the test.

Nevertheless, some of the components and systems that distinguish petrol and diesel cars from EVs can ultimately contribute to defects as vehicles age.

Electric cars also do not undergo the same exhaust emissions checks as combustion-powered vehicles because they have no exhaust emissions system.

As mileage increases, differences in vehicle construction and drivetrain complexity could therefore increasingly affect the defects appearing during MOT tests.

EVs still have components that wear out

The figures certainly do not mean electric cars become maintenance-free once they reach 60,000 miles.

EVs still rely on many of the same safety-critical components inspected during an MOT as any other car.

These include tyres, suspension components, steering, wheel bearings, brakes, lighting, seat belts and structural components.

Tyres and suspension are particularly important areas for garages and EV owners to monitor.

Electric cars can be relatively heavy because of their traction batteries, while the instant torque available from electric motors can also place significant demands on tyres.

Regenerative braking can reduce reliance on conventional friction brakes during everyday driving, but discs, pads, calipers and other braking components still require inspection and maintenance.

In some circumstances, reduced use of friction brakes can introduce its own maintenance considerations, including corrosion.

So while the high-mileage MOT figures are encouraging for EVs, they should not be interpreted as evidence that servicing and preventative maintenance are less important.

MOT results don’t tell us about battery health

There is another major limitation to the findings.

An MOT does not measure the health of an electric vehicle’s traction battery.

A car could pass its MOT while having experienced significant battery degradation.

The test also does not tell a prospective buyer how much usable battery capacity remains, what real-world range the vehicle can achieve, how quickly it charges or whether it has experienced software or other faults outside the scope of the MOT.

The BVRLA therefore says battery health information should be considered alongside roadworthiness when assessing an individual used EV.

This distinction is particularly important as increasing numbers of first-generation and early mass-market electric cars reach the used market.

A strong MOT history is useful evidence about how a vehicle has been maintained and its roadworthiness, but it cannot provide a complete picture of EV condition.

Older EVs also appear to remain in use

The research identified another interesting trend among older vehicles.

At 15 years old, 94.6% of electric cars in the analysis returned for another MOT compared with 88.1% of petrol cars.

That does not mean every vehicle that failed to return had been scrapped.

Cars can disappear from MOT records for several reasons, including being exported or declared SORN.

Nevertheless, the figures provide another indication that older electric cars are remaining in service rather than automatically disappearing from Britain’s roads as they age.

The analysis also found EVs recording higher median annual mileages than petrol cars at every vehicle age between four and 16 years.

At 12 years old, for example, the median annual mileage was approximately 4,920 miles for electric cars compared with 4,410 miles for petrol cars.

What does this mean for used EV buyers?

One of the biggest implications of the research could be for the developing used electric vehicle market.

High mileage has traditionally had a major influence on used-car values and buyer confidence.

Motorists often assume a car with 100,000 miles will inevitably be substantially more troublesome than an otherwise similar lower-mileage example.

The MOT figures suggest mileage alone may be an increasingly poor indicator of the roadworthiness of an electric vehicle.

That does not mean motorists should ignore mileage when buying an EV.

Vehicle condition, servicing and maintenance history, battery health, charging history, tyres, suspension and previous MOT records should all form part of the assessment.

But a well-maintained electric car showing 80,000, 100,000 or even 120,000 miles should not necessarily be dismissed simply because of the number displayed on its odometer.

What does it mean for MOT testers and garages?

For MOT stations and independent garages, the figures provide another indication of how the UK’s changing vehicle parc could alter workshop workloads.

As increasing numbers of EVs reach higher mileages and greater ages, garages are likely to encounter more electric cars requiring conventional wear-and-tear work.

The powertrain may be different, but tyres, brakes, suspension, steering and other mechanical components still need inspection, repair and replacement.

EV capability is therefore becoming increasingly relevant even for workshops that do not specialise in battery or high-voltage repairs.

The MOT itself is also likely to become an increasingly useful source of real-world evidence about how Britain’s growing EV fleet behaves as it ages.

47.4 million MOT tests provide valuable real-world evidence

The scale of the research is significant.

Rather than relying on owner surveys or manufacturer reliability claims, the analysis examined 47.4 million MOT tests using official MOT data.

DVSA’s anonymised MOT dataset includes test outcomes, vehicle make and model, odometer readings and reasons for failure, providing researchers with a substantial source of real-world roadworthiness information.

The results don’t prove that electric cars are universally more reliable than petrol cars.

An MOT cannot measure every aspect of reliability, and it does not assess EV battery capacity or charging performance.

What the figures do show is something more specific and potentially important:

once comparable vehicles move beyond around 60,000 miles, electric cars in the analysis increasingly recorded lower MOT failure rates than petrol cars.

For cars with 90,000 to 120,000 miles, the difference was already substantial – 16.5% of EVs failing compared with 22.1% of petrol cars.

And beyond 120,000 miles, the gap widened further.

For motorists worried that a high-mileage electric car will inevitably become unreliable as the miles accumulate, the UK’s MOT records provide some compelling evidence that the reality may be rather different.

External sources:

BVRLA – Used EV Week and research programme

DVSA / data.gov.uk – Anonymised MOT tests and results dataset

The Independent – Electric cars beat petrol models as the miles pile up

Automotive World – EVs outperform petrol in MOT tests above 60,000 miles