MOT failure rates by age: when cars start to go wrong
How the chance of failing an MOT rises from a car's third birthday to its twentieth, and what that means when you buy used.
By the CarComparison team · Updated · How we research
A car's first MOT is at three years old. In 2024, 12.7% of three-year-old cars failed it first time. By 9, the failure rate had doubled, and it carried on climbing until about 18, when 43.7% of cars failed. This guide shows the whole curve, built from 31 million tests.
The years when things start to go wrong
The failure rate rises fastest between about seven and eleven years old. The steepest single year is age 10, when it goes up 3.5 percentage points. That's when the parts that wear slowly, like suspension springs, ball joints and bushes, start to reach the end of their life, on top of the bulbs, tyres and wipers that fail at any age.
| Age | Failed first time | Tests |
|---|---|---|
| 3 years | 12.7% | 1,894,214 |
| 4 years | 14.0% | 1,955,533 |
| 5 years | 16.1% | 2,492,768 |
| 6 years | 18.7% | 2,499,726 |
| 7 years | 21.5% | 2,658,986 |
| 8 years | 24.7% | 2,675,024 |
| 9 years | 28.0% | 2,530,124 |
| 10 years | 31.5% | 2,261,405 |
| 11 years | 34.3% | 1,956,652 |
| 12 years | 36.8% | 1,705,135 |
| 13 years | 39.2% | 1,569,105 |
| 14 years | 41.1% | 1,493,695 |
| 15 years | 42.3% | 1,212,360 |
| 20 years | 43.2% | 432,736 |
Why it levels off after 18
The rate stops rising for the oldest cars, and that isn't because old cars get more reliable. Cars that are expensive to keep on the road tend to be scrapped, so the ones still being tested at 18 or 20 are mostly those whose owners look after them. Keep that in mind when comparing very old cars: they're the survivors.
The model matters more than the age
Age is only the average. At 10 years old, among models with at least 5,000 tests at that age, the best and worst are far apart:
- Honda CR-V: 18.0% failed at 10 years
- Audi TT: 18.1% failed at 10 years
- Honda Jazz: 18.3% failed at 10 years
- Renault Megane: 48.9% failed at 10 years
- Citroen DS3: 47.0% failed at 10 years
- Renault Clio: 45.3% failed at 10 years
A well-chosen ten-year-old car can be as dependable as an average six-year-old. That's why our reliability scores compare each model with the average car of the same age and mileage, rather than with all cars.
What this means if you're buying used
- Expect running repairs to rise noticeably once a car passes seven or eight years old, especially suspension and brakes.
- Look at the car's own MOT history, not just the model: advisories for corrosion, suspension or brakes are the next fails.
- An older car from a model with a strong record can be better value than a newer one with a poor one.
"Failed first time" means the car failed its first MOT test of the year, before any repairs. Cars aged 3 to 20, 2024.