The top 10 in this list, model by model
1 · 64% fewer MOT fails
Audi A8
Why it ranks here: 64% fewer MOT fails than cars the same age and mileage (ratio 0.36, 95% CI 0.35–0.38), from 17,020 MOT tests at 6 to 10 years. At typical mileage its rate would be about 8.4% (8.0%–8.8%), against 23.2% for all cars at the same ages; raw (its own ages and mileage) 9.2%. Rank range 1–2.
Check before you buy: fails on number plates and VIN 1.3–1.8× as often as cars the same age (170 fails in 37,500 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at an executive car; the ones tested were mostly diesel.
2 · 60% fewer MOT fails
Lexus GS
Why it ranks here: 60% fewer MOT fails than cars the same age and mileage (ratio 0.40, 95% CI 0.37–0.43), from 8,595 MOT tests at 6 to 10 years. At typical mileage its rate would be about 9.7% (9.1%–10.3%), against 24.3% for all cars at the same ages; raw (its own ages and mileage) 9.8%. Rank range 1–4.
Check before you buy: no part fails significantly more often than on cars the same age (ages 3 to 15).
Suits: buyers looking at an executive car; the ones tested were 52% hybrid, 47% petrol.
3 · 58% fewer MOT fails
Lexus RX
Why it ranks here: 58% fewer MOT fails than cars the same age and mileage (ratio 0.42, 95% CI 0.41–0.43), from 35,359 MOT tests at 6 to 10 years. At typical mileage its rate would be about 9.6% (9.3%–9.9%), against 22.9% for all cars at the same ages; raw (its own ages and mileage) 9.9%. Rank range 2–4.
Check before you buy: no part fails significantly more often than on cars the same age (ages 3 to 15).
Suits: buyers looking at a large SUV; the ones tested were mostly hybrid.
4 · 54% fewer MOT fails
BMW M5
Why it ranks here: 54% fewer MOT fails than cars the same age and mileage (ratio 0.46, 95% CI 0.42–0.50), from 4,448 MOT tests at 8 to 10 years. At typical mileage its rate would be about 12.5% (11.5%–13.5%), against 27.1% for all cars at the same ages; raw (its own ages and mileage) 12.0%. Rank range 2–6.
Check before you buy: no part fails significantly more often than on cars the same age (ages 3 to 15).
Suits: buyers looking at an executive car; the ones tested were mostly petrol.
5 · 50% fewer MOT fails
Porsche Macan
Why it ranks here: 50% fewer MOT fails than cars the same age and mileage (ratio 0.50, 95% CI 0.48–0.51), from 63,455 MOT tests at 6 to 10 years. At typical mileage its rate would be about 10.3% (10.1%–10.6%), against 20.9% for all cars at the same ages; raw (its own ages and mileage) 10.4%. Rank range 4–7.
Check before you buy: fails on number plates and VIN 1.7–2.1× as often as cars the same age (492 fails in 115,297 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at a family SUV; the ones tested were 70% petrol, 30% diesel.
6 · 49% fewer MOT fails
Porsche Panamera
Why it ranks here: 49% fewer MOT fails than cars the same age and mileage (ratio 0.51, 95% CI 0.48–0.53), from 13,316 MOT tests at 6 to 10 years. At typical mileage its rate would be about 11.7% (11.2%–12.2%), against 23.0% for all cars at the same ages; raw (its own ages and mileage) 11.9%. Rank range 4–8.
Check before you buy: no part fails significantly more often than on cars the same age (ages 3 to 15).
Suits: buyers looking at an executive car; the ones tested were 35% petrol, 34% diesel.
7 · 48% fewer MOT fails
Lexus IS
Why it ranks here: 48% fewer MOT fails than cars the same age and mileage (ratio 0.52, 95% CI 0.50–0.53), from 42,193 MOT tests at 6 to 10 years. At typical mileage its rate would be about 12.3% (12.0%–12.6%), against 23.7% for all cars at the same ages; raw (its own ages and mileage) 12.8%. Rank range 5–8.
Check before you buy: no part fails significantly more often than on cars the same age (ages 3 to 15).
Suits: buyers looking at an executive car; the ones tested were 48% petrol, 36% hybrid.
8 · 47% fewer MOT fails
BMW 7 Series
Why it ranks here: 47% fewer MOT fails than cars the same age and mileage (ratio 0.53, 95% CI 0.51–0.55), from 24,150 MOT tests at 6 to 10 years. At typical mileage its rate would be about 11.6% (11.2%–12.0%), against 21.9% for all cars at the same ages; raw (its own ages and mileage) 12.7%. Rank range 6–11.
Check before you buy: fails on road wheels 3.9–4.5× as often as cars the same age (761 fails in 56,039 MOT tests at ages 3 to 15, not mileage-adjusted); fails on number plates and VIN 1.6–2.0× as often as cars the same age (277 fails in 56,039 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at an executive car; the ones tested were 71% diesel, 20% petrol.
9 · 45% fewer MOT fails
Lexus NX
Why it ranks here: 45% fewer MOT fails than cars the same age and mileage (ratio 0.55, 95% CI 0.54–0.56), from 53,880 MOT tests at 6 to 10 years. At typical mileage its rate would be about 11.4% (11.2%–11.7%), against 20.7% for all cars at the same ages; raw (its own ages and mileage) 11.5%. Rank range 8–13.
Check before you buy: no part fails significantly more often than on cars the same age (ages 3 to 15).
Suits: buyers looking at a family SUV; the ones tested were mostly hybrid.
10 · 44% fewer MOT fails
Porsche Cayenne
Why it ranks here: 44% fewer MOT fails than cars the same age and mileage (ratio 0.56, 95% CI 0.55–0.57), from 45,108 MOT tests at 6 to 10 years. At typical mileage its rate would be about 12.8% (12.6%–13.2%), against 23.0% for all cars at the same ages; raw (its own ages and mileage) 13.7%. Rank range 8–13.
Check before you buy: fails on number plates and VIN 2.2–2.6× as often as cars the same age (647 fails in 99,151 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at a large SUV; the ones tested were 44% petrol, 43% diesel.
How we rank
43,731,107 MOT tests from 2022–2025 of cars 6 to 10 years old. For each model and age, the tests are split into 6 mileage bands (<30k, 30-60k, 60-90k, 90-120k, 120-150k, 150k+); the expected fails are what all cars of that age would fail in the same bands, corrected to the model's own mix of test years. The ratio of the model's fails to the expected fails sets its place. The adjusted rate is that ratio times the all-car rate at the model's own ages, so it reads against that rate: a model tested only at 3 to 5 years is compared with young cars, not with this list's average.
The 95% intervals cover sampling error only (Wilson intervals). A model is called fewer or more only when its interval is at least 20% from the all-car rate, overall and at 3 or more ages ("close to average" when the interval excludes the all-car rate by less); awards use the same rule. Test years: Each model's expected fails therefore use its own mix of test years 2022–2025, age by age; the mileage bands themselves pool the four years, which can leave a small bias in favour of models first sold late in the window. Generations of a model are pooled unless the data splits them; each row says which years it covers. How we compare
Limitation: MOT tests record roadworthiness defects on the test day. They do not record breakdowns, engine or gearbox faults, or repair costs, and they cannot separate design from upkeep: a model whose owners service it before every MOT looks better here. Only cars still on the road are tested.