The top 10 in this list, model by model
1 · About average
Vauxhall Cascada
Why it ranks here: About as many MOT fails as cars the same age and mileage (ratio 0.98, 95% CI 0.95–1.02), from 8,964 MOT tests at 7 to 11 years. At typical mileage its rate would be about 26.0% (25.1%–27.0%), against 26.5% for all cars at the same ages; raw (its own ages and mileage) 24.2%. Rank range 1–1.
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 sports car; the ones tested were 50% diesel, 50% petrol.
2 · About average
Vauxhall Insignia
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.03, 95% CI 1.03–1.03), from 820,732 MOT tests at 3 to 15 years. At typical mileage its rate would be about 28.6% (28.5%–28.7%), against 27.8% for all cars at the same ages; raw (its own ages and mileage) 31.5%. Rank range 2–3.
Check before you buy: fails on suspension 1.30–1.31× as often as cars the same age (92,226 fails in 828,215 MOT tests at ages 3 to 15, not mileage-adjusted); fails on tyres 1.28–1.30× as often as cars the same age (70,831 fails in 828,215 MOT tests at ages 3 to 15, not mileage-adjusted); fails on emissions and leaks 1.28–1.31× as often as cars the same age (27,736 fails in 828,215 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at an executive car; the ones tested were mostly diesel.
3 · About average
Vauxhall Viva
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.03, 95% CI 1.02–1.04), from 153,068 MOT tests at 3 to 10 years. At typical mileage its rate would be about 19.8% (19.6%–20.0%), against 19.2% for all cars at the same ages; raw (its own ages and mileage) 16.8%. Rank range 2–4.
Check before you buy: fails on visibility 1.5–1.6× as often as cars the same age (7,882 fails in 154,054 MOT tests at ages 3 to 15, not mileage-adjusted); fails on body and structure 1.2–1.3× as often as cars the same age (2,015 fails in 154,054 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at a city car; the ones tested were mostly petrol.
4 · About average
Vauxhall Astra
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.04, 95% CI 1.04–1.04), from 2,174,196 MOT tests at 3 to 15 years. At typical mileage its rate would be about 30.3% (30.3%–30.4%), against 29.1% for all cars at the same ages; raw (its own ages and mileage) 31.3%. Rank range 3–4.
Check before you buy: fails on emissions and leaks 1.42–1.44× as often as cars the same age (89,951 fails in 2,187,577 MOT tests at ages 3 to 15, not mileage-adjusted); fails on body and structure 1.2–1.3× as often as cars the same age (79,106 fails in 2,187,577 MOT tests at ages 3 to 15, not mileage-adjusted); fails on brakes 1.21–1.22× as often as cars the same age (166,535 fails in 2,187,577 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at a family hatchback; the ones tested were 69% petrol, 31% diesel.
5 · About average
Vauxhall Grandland
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.06, 95% CI 1.05–1.08), from 242,396 MOT tests at 3 to 7 years. At typical mileage its rate would be about 14.2% (14.1%–14.4%), against 13.4% for all cars at the same ages; raw (its own ages and mileage) 14.4%. Rank range 5–6.
Check before you buy: fails on body and structure 2.9–3.1× as often as cars the same age (2,797 fails in 243,753 MOT tests at ages 3 to 15, not mileage-adjusted); fails on seat belts and airbags 1.9–2.1× as often as cars the same age (1,486 fails in 243,753 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at a family SUV; the ones tested were 75% petrol, 23% diesel.
6 · About average
Vauxhall Vectra
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.07, 95% CI 1.06–1.08), from 45,857 MOT tests at 13 to 15 years. At typical mileage its rate would be about 44.7% (44.3%–45.1%), against 41.9% for all cars at the same ages; raw (its own ages and mileage) 46.6%. Rank range 5–6.
Check before you buy: fails on brakes 1.77–1.84× as often as cars the same age (8,383 fails in 46,260 MOT tests at ages 3 to 15, not mileage-adjusted); fails on emissions and leaks 1.4–1.5× as often as cars the same age (3,696 fails in 46,260 MOT tests at ages 3 to 15, not mileage-adjusted); fails on body and structure 1.3–1.4× as often as cars the same age (3,696 fails in 46,260 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at an executive car; the ones tested were 64% petrol, 36% diesel.
7 · About average
Vauxhall Meriva
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.10, 95% CI 1.09–1.10), from 314,918 MOT tests at 5 to 15 years. At typical mileage its rate would be about 35.4% (35.2%–35.6%), against 32.3% for all cars at the same ages; raw (its own ages and mileage) 33.9%. Rank range 7–7.
Check before you buy: fails on suspension 1.32–1.34× as often as cars the same age (46,356 fails in 317,826 MOT tests at ages 3 to 15, not mileage-adjusted); fails on emissions and leaks 1.29–1.33× as often as cars the same age (13,731 fails in 317,826 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at an MPV; the ones tested were mostly petrol.
8 · About average
Vauxhall Zafira
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.11, 95% CI 1.10–1.11), from 682,856 MOT tests at 4 to 15 years. At typical mileage its rate would be about 34.3% (34.2%–34.4%), against 31.0% for all cars at the same ages; raw (its own ages and mileage) 35.8%. Rank range 8–8.
Check before you buy: fails on emissions and leaks 2.1–2.2× as often as cars the same age (45,360 fails in 687,282 MOT tests at ages 3 to 15, not mileage-adjusted); fails on visibility 1.3–1.4× as often as cars the same age (41,829 fails in 687,282 MOT tests at ages 3 to 15, not mileage-adjusted); fails on tyres 1.26–1.28× as often as cars the same age (59,939 fails in 687,282 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at an MPV; the ones tested were 66% petrol, 34% diesel.
9 · About average
Vauxhall Crossland
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.14, 95% CI 1.13–1.15), from 228,380 MOT tests at 3 to 8 years. At typical mileage its rate would be about 15.2% (15.0%–15.3%), against 13.3% for all cars at the same ages; raw (its own ages and mileage) 14.6%. Rank range 9–9.
Check before you buy: fails on body and structure 8.2–8.6× as often as cars the same age (7,414 fails in 229,410 MOT tests at ages 3 to 15, not mileage-adjusted); fails on brakes 1.8–1.9× as often as cars the same age (9,373 fails in 229,410 MOT tests at ages 3 to 15, not mileage-adjusted); fails on emissions and leaks 1.4–1.6× as often as cars the same age (2,438 fails in 229,410 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at a small SUV; the ones tested were mostly petrol.
10 · About average
Vauxhall Agila
Why it ranks here: No clear difference from cars the same age and mileage by our 20% rule (ratio 1.17, 95% CI 1.16–1.18), from 102,705 MOT tests at 8 to 15 years. At typical mileage its rate would be about 42.0% (41.6%–42.3%), against 35.8% for all cars at the same ages; raw (its own ages and mileage) 35.7%. Rank range 10–10.
Check before you buy: fails on brakes 1.5–1.6× as often as cars the same age (12,787 fails in 103,407 MOT tests at ages 3 to 15, not mileage-adjusted); fails on suspension 1.4–1.5× as often as cars the same age (19,276 fails in 103,407 MOT tests at ages 3 to 15, not mileage-adjusted); fails on visibility 1.27–1.33× as often as cars the same age (6,871 fails in 103,407 MOT tests at ages 3 to 15, not mileage-adjusted).
Suits: buyers looking at a city car; the ones tested were mostly petrol.
How we rank
9,263,145 MOT tests from 2022–2025 of cars 3 to 15 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.