What does the 2026 high-mileage EV reliability study show?
The study analysed 47.4 million MOT tests. It found little difference between battery-electric and petrol cars at lower mileages, but EV failure rates began separating more clearly after roughly 60,000 miles. At 90,000–120,000 miles, 16.5% of EVs failed versus 22.1% of petrol cars. These figures measure statutory roadworthiness; MOT data does not measure battery health or battery degradation.
High mileage alone should not make you reject an EV. In the British MOT analysis, battery-electric cars aged 3–8 had slightly higher failure rates than petrol cars in the two lowest mileage bands, then lower failure rates in every band from 40,000 miles upward. The gap was largest above 120,000 miles.
That does not prove the battery is healthy, repairs will be cheap, or every high-mileage EV is reliable. It says that mileage alone was a poor proxy for statutory roadworthiness in this dataset. A real purchase still needs battery state of health, age, charging history and an individual inspection.
Brakes, tyres, suspension, steering, lights and other statutory inspection items—not total ownership reliability.
Capacity loss associated with model, charging, climate and usage—not whether the whole car passes inspection.
How long vehicles remain in use; newer generations require projections because their completed lifetimes cannot yet be observed.
Are high-mileage EVs reliable?
The best current answer is conditional. High-mileage EVs performed well on roadworthiness in a large British MOT dataset, especially when vehicles of the same age and mileage were compared. Battery condition and costly non-MOT faults require separate evidence.
The September 2026 BVRLA / New AutoMotive report ↗ analysed 47,406,312 MOT tests completed in Great Britain between July 2024 and July 2026. Its main controlled comparison covers cars aged 3–8, cross-tabulated by mileage. Implausible odometer readings were removed and cells with fewer than 100 vehicles were suppressed.
High-mileage EV versus petrol MOT failure rates
Primary / published data
The chart uses every mileage band in the report’s controlled table—not only the bands favourable to EVs. At low mileage, the EV rate is slightly higher. The direction reverses in the 40,000–60,000-mile band and the difference widens in the higher bands.
| Mileage band | EV failure rate | Petrol failure rate | Percentage-point difference | Relative difference | Data source |
|---|---|---|---|---|---|
| 0–20,000 miles | 8.7% | 8.0% | +0.7 pp | +8.8% | BVRLA / New AutoMotive; DVSA MOT records |
| 20,000–40,000 miles | 12.0% | 11.7% | +0.3 pp | +2.6% | BVRLA / New AutoMotive; DVSA MOT records |
| 40,000–60,000 miles | 14.1% | 15.5% | −1.4 pp | −9.0% | BVRLA / New AutoMotive; DVSA MOT records |
| 60,000–90,000 miles | 16.1% | 19.1% | −3.0 pp | −15.7% | BVRLA / New AutoMotive; DVSA MOT records |
| 90,000–120,000 miles | 16.5% | 22.1% | −5.6 pp | −25.3% | BVRLA / New AutoMotive; DVSA MOT records |
| 120,000+ miles | 16.0% | 23.5% | −7.5 pp | −31.9% | BVRLA / New AutoMotive; DVSA MOT records |
When does the EV–petrol reliability gap appear?
KalQLater calculation
The first lower EV failure rate appears in the 40,000–60,000-mile band: 14.1% for EVs and 15.5% for petrol, a difference of −1.4 percentage points or −9.0% relative to petrol. The relative difference then moves to −15.7% at 60,000–90,000 miles, −25.3% at 90,000–120,000 miles and −31.9% above 120,000 miles.
EV failure rate − petrol failure rate(EV failure rate − petrol failure rate) ÷ petrol failure rate × 100For example, at 90,000–120,000 miles: 16.5% − 22.1% = −5.6 percentage points. Dividing −5.6 by 22.1 gives −25.3%, so the EV failure rate was about 25% lower relative to petrol—not 5.6% lower.
What happens to an EV battery at high mileage?
The MOT dataset cannot answer this. An MOT tests statutory roadworthiness. It does not measure usable battery capacity, electrochemical degradation, charging performance, software faults or battery replacement risk.
For battery health, we therefore use a separate Geotab telematics analysis ↗. Geotab’s expanded dataset covered more than 22,700 EVs across 21 models and reported battery state-of-health trends by charging behaviour, climate and use. It is an aggregated company study, not a peer-reviewed census of all EV batteries.
Primary / published data
| Metric | Observed value | What it means | Source |
|---|---|---|---|
| Study sample | More than 22,700 EVs across 21 models | Large aggregated telematics sample; it is not a census of every EV model. | Geotab, 2026 |
| Average annual degradation | 2.3% per year | Average capacity loss across the expanded 2025 dataset, published in 2026. | Geotab, 2026 |
| Low DC-fast-charge frequency | 1.5% per year | Vehicles with DC fast charging below 12% of charging sessions. | Geotab, 2026 |
| High DC-fast-charge frequency | 2.5% per year | Vehicles with DC fast charging above 12% of charging sessions. | Geotab, 2026 |
| High-frequency, high-power DC charging | 3.0% per year | Within frequent DCFC users, more than 40% of DC sessions exceeded 100 kW. | Geotab, 2026 |
| Hot-climate difference | 0.4% faster per year | Geotab's reported difference between its hot- and mild-climate groups. | Geotab, 2026 |
How much battery degradation should you expect?
There is no single safe percentage for every high-mileage EV. Geotab’s aggregate was 2.3% capacity loss per year, but its operating groups ranged from 1.5% to 3.0% per year and model-level design also mattered. Mileage, years, energy throughput and charging conditions are related but not interchangeable.
Illustrative KalQLater calculation
| Illustrative annual rate | Straight-line capacity loss after 5 years | Illustrative capacity remaining | Calculation |
|---|---|---|---|
| 1.5% | 7.5 percentage points | 92.5% | 100 − (1.5 × 5) |
| 2.3% | 11.5 percentage points | 88.5% | 100 − (2.3 × 5) |
| 3.0% | 15.0 percentage points | 85.0% | 100 − (3.0 × 5) |
Does fast charging damage an EV battery?
In Geotab’s observational cohorts, frequent and higher-power DC charging was associated with faster average degradation. Low-frequency DCFC vehicles averaged 1.5% per year, high-frequency DCFC vehicles 2.5%, and the frequent/high-power group 3.0%.
That is decision-relevant, but it is not a randomized experiment. Vehicle design, chemistry, thermal management, usage intensity and charging behaviour can overlap. The defensible used-EV question is therefore not “Was it ever fast charged?” but “How dependent was it on frequent high-power charging, and what does its current battery-health test show?”
Do EVs actually last as long as petrol cars?
Peer-reviewed research
The Nature Communications study by Daniel Mehlig and Iain Staffell ↗, published 21 September 2026, uses British MOT histories to examine real-world mileage and vehicle survival. Its central reliability lesson is generational: early BEVs and current BEVs should not be treated as one timeless technology cohort.
The paper reports this relative to conventional vehicles. It is historical evidence about early cohorts, not a verdict on every current model.
The study projects annual mileage and lifetime matching conventional vehicles. Cars bought in 2026 cannot yet have completed that lifetime.
The authors publish a data and code trail ↗ for the mileage, survival and projection analysis. KalQLater does not convert the projection into a guaranteed number of years because it is conditional on recent trends continuing.
Is 100,000 miles high for an electric car?
It is high mileage in normal used-car language, but it is not an automatic end-of-life signal. The MOT report directly includes 90,000–120,000-mile and 120,000+ bands. EVs aged 3–8 recorded lower MOT failure rates than same-age petrol cars in both.
That evidence changes the prior question from “Is 100,000 miles too much?” to “What condition is this 100,000-mile car in?” Battery SOH, remaining warranty, tyres, suspension, accident history and inspection records answer that second question.
Is a high-mileage EV more reliable than a petrol car?
On this report’s roadworthiness measure, high-mileage EVs had lower failure rates. At 90,000–120,000 miles the figures were 16.5% for EVs and 22.1% for petrol; above 120,000 miles they were 16.0% and 23.5%.
That does not establish lower total repair cost, healthier batteries, fewer software problems or superiority for every model. “Lower MOT failure rate” is the accurate conclusion. “EVs are universally more reliable” is not.
Should you buy an EV with 100,000 miles?
Do not accept or reject it from the odometer alone. Treat mileage as one screening variable and demand evidence about the expensive, safety-critical and model-specific risks.
| Factor | Why it matters | What to check |
|---|---|---|
| Mileage | Shows accumulated use, but not how the car was used or maintained. | Read it with age, inspection history and condition—not as a verdict. |
| Battery state of health | Estimates remaining usable capacity and likely range. | Request a current diagnostic report and learn how that model reports SOH. |
| Battery warranty | Coverage limits vary by age, mileage and capacity threshold. | Verify the exact vehicle identification number, terms, transferability and remaining cover. |
| Charging history | Geotab's cohorts differed by DCFC frequency and charging power. | Ask whether fast charging was occasional or the vehicle's routine charging pattern. |
| Climate history | Heat exposure was associated with faster degradation in Geotab's data. | Check where the car operated and whether the battery has active thermal management. |
| Service and inspection history | Recurring advisories can reveal condition better than mileage alone. | Review MOT or inspection records, maintenance invoices and unresolved recalls. |
| Tyres | The MOT analysis found more tyre defects for EVs overall. | Inspect tread depth, evenness, age and whether tyres meet the vehicle specification. |
| Suspension | High mileage still means component wear, even though the report found no EV-wide suspension penalty. | Listen for noise, inspect alignment and have joints, bushes and dampers checked. |
| Accident history | Damage and repair quality are individual-vehicle risks absent from fleet averages. | Check title/history records and arrange an independent structural inspection. |
| Vehicle age | Age and mileage interact; early EV generations differ from newer ones. | Compare the car with the correct model year, battery chemistry and technology generation. |
Should you buy a used EV with high mileage?
A high-mileage EV can be a reasonable purchase when its battery health, condition, history and price support the decision. The fleet-level evidence removes mileage as an automatic rejection rule; it does not remove the need for vehicle-level due diligence.
Compare the usable range at current SOH with your real journeys, price likely wear items, confirm warranty terms and obtain an independent inspection. A lower purchase price is not compensation for an unknown battery if the uncertainty matters to your use case.
What matters more than mileage when buying a used EV?
Battery state of health and individual vehicle condition are usually more decision-relevant than mileage alone. The combined evidence suggests seven layers worth checking:
Current inspection result, advisories and safety defects.
Measured usable capacity, range and diagnostic warnings.
Model year, chemistry, thermal management and known model issues.
Frequency and power of routine DC fast charging.
Long-term heat exposure and battery cooling design.
Wear, alignment, bushes, dampers and correct tyre specification.
Maintenance, accidents, ownership, recalls and warranty claims.
What the high-mileage EV reliability headline doesn't tell you
The inspection does not measure usable battery capacity or electrochemical degradation.
Sixteen percent of EVs above 120,000 miles still failed in the controlled table.
Model, age, maintenance, prior damage and usage can move an individual far from the average.
The headline comparison controls for both; a simple all-fleet rate does not.
Early-generation longevity should not be silently assigned to newer BEVs—or vice versa.
Software, charging hardware, unscheduled repairs and warranty events can sit outside the test.
No replacement probability can be calculated from MOT failure rates.
The report found roughly 1.8 times as many tyre defects for EVs overall, despite lower high-mileage failure rates.
Methodology and calculations
- Mileage bands: We used all six bands in the report’s age-and-mileage-controlled table: 0–20k, 20–40k, 40–60k, 60–90k, 90–120k and 120k+ miles.
- Comparable population: The main chart and table retain the report’s 3–8-year vehicle scope. We do not mix it with the misleading unadjusted all-fleet comparison.
- Point difference: EV failure rate minus petrol failure rate. A negative result means the EV rate was lower.
- Relative difference: Point difference divided by the petrol rate, multiplied by 100. Calculations use unrounded source percentages and are displayed to one decimal place.
- Battery interpretation: Geotab’s annual degradation rates remain battery-health cohort averages. We do not convert them into MOT reliability or a mileage-specific failure probability.
- Illustrative retention: The five-year table subtracts the annual group average five times only to illustrate scale. It is explicitly not a fitted battery-degradation curve.
- Longevity: The Nature study’s early-generation finding is labelled observed; parity for 2026 purchases is labelled a conditional study projection.
- No causal claim: Differences between fuel types or charging cohorts are associations in observational data.
Read the broader KalQLater methodology and editorial standards.
Limitations
- MOT data measures statutory roadworthiness failures, not total repair frequency or cost.
- MOT tests do not directly measure battery state of health, degradation, charging performance or software reliability.
- The controlled mileage table covers British vehicles aged 3–8; other ages, countries and inspection regimes may differ.
- Fleet-level averages do not guarantee the condition or reliability of an individual model or vehicle.
- Geotab’s battery sample covers specific models and operating conditions; aggregated rates hide model-level variation.
- Charging, climate and degradation associations do not establish causation.
- New-generation lifetime estimates are projections, not completed observed lifetimes.
- Road exit can include scrappage, export or an off-road declaration, so disappearance from MOT data is not identical to mechanical death.
If a source or calculation needs correction, use KalQLater’s corrections policy.
Sources and verification trail
Each source answers a different part of the question. The MOT report supplies roadworthiness rates, Geotab supplies battery-health cohorts, and the peer-reviewed Nature paper supplies mileage and survival analysis. They are not merged into one synthetic “reliability score.”