The top 10 in this list, model by model
1 · 67% fewer MOT fails
Audi A8
Why it ranks here: 67% fewer MOT fails than cars the same age and mileage (ratio 0.33, 95% CI 0.32–0.35), from 16,130 MOT tests at 8 to 12 years. At typical mileage its rate would be about 9.8% (9.3%–10.2%), against 29.3% for all cars at the same ages; raw (its own ages and mileage) 10.6%. Rank range 1–1.
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 0.38–0.42), from 8,989 MOT tests at 8 to 12 years. At typical mileage its rate would be about 11.6% (10.9%–12.3%), against 28.9% for all cars at the same ages; raw (its own ages and mileage) 11.8%. Rank range 2–3.
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 · 55% fewer MOT fails
BMW M5
Why it ranks here: 55% fewer MOT fails than cars the same age and mileage (ratio 0.45, 95% CI 0.42–0.48), from 5,663 MOT tests at 8 to 11 years. At typical mileage its rate would be about 12.6% (11.8%–13.5%), against 28.2% for all cars at the same ages; raw (its own ages and mileage) 12.2%. 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.
4 · 53% fewer MOT fails
Porsche Panamera
Why it ranks here: 53% fewer MOT fails than cars the same age and mileage (ratio 0.47, 95% CI 0.45–0.49), from 12,016 MOT tests at 8 to 12 years. At typical mileage its rate would be about 13.7% (13.1%–14.3%), against 29.2% for all cars at the same ages; raw (its own ages and mileage) 14.0%. Rank range 3–7.
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.
5 · 53% fewer MOT fails
Lexus RX
Why it ranks here: 53% fewer MOT fails than cars the same age and mileage (ratio 0.47, 95% CI 0.46–0.48), from 35,019 MOT tests at 8 to 12 years. At typical mileage its rate would be about 14.0% (13.7%–14.4%), against 29.9% for all cars at the same ages; raw (its own ages and mileage) 14.6%. Rank range 3–6.
Check before you buy: no part fails significantly more often than on cars the same age (ages 3 to 15).
Suits: buyers looking at a large SUV; the ones tested were mostly hybrid.
6 · 50% fewer MOT fails
Lexus NX
Why it ranks here: 50% fewer MOT fails than cars the same age and mileage (ratio 0.50, 95% CI 0.49–0.52), from 22,925 MOT tests at 8 to 10 years. At typical mileage its rate would be about 12.2% (11.8%–12.6%), against 24.2% for all cars at the same ages; raw (its own ages and mileage) 12.3%. Rank range 5–12.
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.
7 · 49% fewer MOT fails
Audi S3
Why it ranks here: 49% fewer MOT fails than cars the same age and mileage (ratio 0.51, 95% CI 0.47–0.55), from 3,629 MOT tests at 9 to 11 years. At typical mileage its rate would be about 15.3% (14.1%–16.4%), against 29.9% for all cars at the same ages; raw (its own ages and mileage) 15.6%. Rank range 3–17.
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 hatchback; the ones tested were mostly petrol.
8 · 49% fewer MOT fails
Porsche Cayenne
Why it ranks here: 49% fewer MOT fails than cars the same age and mileage (ratio 0.51, 95% CI 0.50–0.52), from 40,058 MOT tests at 8 to 12 years. At typical mileage its rate would be about 14.8% (14.4%–15.1%), against 28.9% for all cars at the same ages; raw (its own ages and mileage) 15.7%. Rank range 6–12.
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.
9 · 49% fewer MOT fails
Porsche Macan
Why it ranks here: 49% fewer MOT fails than cars the same age and mileage (ratio 0.51, 95% CI 0.50–0.53), from 29,239 MOT tests at 8 to 11 years. At typical mileage its rate would be about 12.5% (12.2%–12.9%), against 24.4% for all cars at the same ages; raw (its own ages and mileage) 12.6%. Rank range 6–13.
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.
10 · 49% fewer MOT fails
Lexus IS
Why it ranks here: 49% fewer MOT fails than cars the same age and mileage (ratio 0.51, 95% CI 0.50–0.53), from 41,596 MOT tests at 8 to 12 years. At typical mileage its rate would be about 14.8% (14.5%–15.2%), against 28.8% for all cars at the same ages; raw (its own ages and mileage) 15.3%. Rank range 6–13.
Check before you buy: no part fails significantly more often than on cars the same age (ages 3 to 15).
Suits: buyers looking at an executive car; the ones tested were 48% petrol, 36% hybrid.
How we rank
39,361,275 MOT tests from 2022–2025 of cars 8 to 12 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.