2021 Mercedes-Benz A MOT pass rate: 92.0% (34,759 tests)

2021-registered Mercedes-Benz As passed 92.0% of 34,759 MOT tests in 2023–2025 — 1.6 points better than all UK cars registered in 2021 (90.4%). This is one of the strongest A years in the age-adjusted MOT ranking, although the individual car still matters more.
92.0%Pass rate, 2021 cars
101.6Age-adjusted index (100 = average)
34,759Tests analysed
28,343 miMedian mileage at test
92.3% / 91.5%Petrol vs diesel pass rate

Is the 2021 A getting worse?

Pass rate of 2021-registered cars across recent test years:

Test yearPass rate
202492.4%
+1.8 vs same-age
202591.6%
+1.4 vs same-age

The raw rate normally falls as cars age. The “vs same-age” figure compares this cohort with all UK cars registered in the same year, so normal ageing is not mistaken for a bad model year.

What fails on a 2021 A

#SystemDefects recordedShare
1Tyres2,23452.4%
2Brakes68116.0%
3Visibility4109.6%
4Lamps, reflectors and electrical equipment2896.8%
5Road Wheels1613.8%
6Suspension1172.7%

All A years compared

Registration yearTestsPass rateVs same-ageMedian mileage
2018 2,502 85.5% -0.8 pts 43,671
2019 125,677 88.5% +0.1 pts 36,944
2020 86,336 90.6% +0.6 pts 29,490
2021 (this page) 34,759 92.0% +1.6 pts 28,343
2022 4,161 92.8% +1.5 pts 21,854

Weighing up which year to buy? See the full ranking: Mercedes-Benz A years to avoid.

Buying a 2021 A? Two checks first

FAQs

Is a 2021 Mercedes-Benz A reliable?

2021-registered examples passed 92.0% of their MOT tests (34,759 tests, 2023–2025), +1.6 points versus all UK cars registered in the same year. At roughly 5 years old with a median 28,343 miles, condition now varies car by car — always check the individual MOT history.

What mileage is too high for a 2021 A?

The median tested example shows 28,343 miles. Anything far beyond that isn't automatically bad — a motorway-mile car with consistent service records often beats a low-mileage school-run car — but price accordingly and scrutinise the mileage trail for gaps or drops.

Source: DVSA Anonymised MOT tests and results, 2023–2025 extracts (96 million Class 4 initial tests; retests excluded). Only vehicles old enough for a routine first MOT are included. Age-adjusted figures compare the model-year cohort with all vehicles of the same registration year tested in the same calendar year. Contains public sector information licensed under OGL v3.0.