Electric, hybrid, petrol or diesel: which is most reliable?
MOT results for cars of the same age by fuel type, and the faults each kind of car fails on most. Electric cars wear tyres, not brakes.
By the CarComparison team · Updated · How we research
Comparing fuel types fairly means comparing cars of the same age: most electric cars on the road are young, and most diesels are old. So we split 2024's MOT results into age bands. Among cars 3 to 5 years old, hybrid cars had the best record, failing 11.4% of first tests, and diesel cars the worst at 17.7%.
Failure rates by fuel and age
| Fuel | 3 to 5 years | 6 to 10 years | 11 to 20 years |
|---|---|---|---|
| Petrol | 13.3% | 23.5% | 40.0% |
| Diesel | 17.7% | 26.3% | 40.2% |
| Hybrid | 11.4% | 17.2% | 25.2%* |
| Electric | 14.1% | 25.9%* | 32.0%* |
* Fewer than 50,000 tests: older electric and hybrid cars are still rare, so treat these as a rough guide.
Hybrids come out best in every age band. Diesels fail most often among younger cars, partly because they tend to cover more miles each year, which wears suspension and brakes faster. These figures aren't adjusted for mileage, unlike our model-by-model reliability scores.
Electric cars fail on different things
The overall rate hides the more interesting story: each kind of car goes wrong in its own way. Among cars 3 to 5 years old:
- Tyres: electric cars failed on tyres in 8.1% of tests, 69% more often thanpetrol cars (4.8%). They're heavy, and their instant torque scrubs tread faster.
- Brakes: electric cars failed on brakes in just 0.9% of tests, against 2.4% for petrol and 3.5% for diesel. Most of their slowing is done by the motor (regenerative braking), so pads and discs last far longer. Hybrids, which also regenerate, are similar at 0.9%.
- Exhaust and emissions: with no exhaust, electric cars almost never fail here. Diesels failed in 1.9% of tests, more than three times petrol's 0.5%: diesel particulate filters and emissions systems are a known weak point.
| Part of the car | Petrol | Diesel | Hybrid | Electric |
|---|---|---|---|---|
| Tyres | 4.8% | 5.5% | 5.1% | 8.1% |
| Visibility | 3.1% | 3.6% | 3.0% | 2.5% |
| Lights and electrics | 2.9% | 5.0% | 2.5% | 2.6% |
| Brakes | 2.4% | 3.5% | 0.9% | 0.9% |
| Suspension | 1.0% | 1.9% | 0.6% | 1.3% |
| Exhaust and emissions | 0.5% | 1.9% | 0.2% | 0.0% |
| Body and structure | 0.4% | 0.8% | 0.2% | 0.2% |
| Seat belts and airbags | 0.3% | 0.4% | 0.2% | 0.2% |
| Steering | 0.3% | 0.3% | 0.1% | 0.1% |
| Wheels | 0.2% | 0.3% | 0.2% | 0.2% |
Share of tests of 3 to 5-year-old cars that failed on at least one fault in each area, 2024.
What it means for you
- Buying electric: budget for tyres. Check the tread on a used EV, and expect to replace tyres sooner than on a petrol car.
- Buying diesel: it suits high mileages, but check the emissions history and whether the car has done enough motorway driving to keep its particulate filter clean.
- Buying hybrid: the best MOT record of any fuel type at every age, with low brake wear.
Within each fuel type, the model matters far more than the fuel. Our reliability ratings compare each model with the average car of the same age and mileage.