Mercedes-Benz A years to avoid — 253,435 MOT tests ranked

No clear negative outlier after correcting for age. Strongest in the data: 2021 or 2022. The ranking uses 253,435 MOT tests across 5 registration years (2023–2025) and compares each year with all UK cars of the same age.

Every A year, ranked

The age-adjusted MOT index sets 100 as the pass rate of all UK cars registered in the same year and tested in the same calendar year. Higher is better. This prevents an old car being labelled a “bad year” simply because it is old.

RankYearIndexVs same-agePass rateTests
1 2021 Strong 101.6 +1.6 pts 92.0% 34,759
2 2022 Strong 101.5 +1.5 pts 92.8% 4,161
3 2020 100.6 +0.6 pts 90.6% 86,336
4 2019 100.1 +0.1 pts 88.5% 125,677
5 2018 99.2 -0.8 pts 85.5% 2,502

How to use this before buying

  • Rankings describe the cohort, not the car. A cherished older example beats a neglected 2021 one — always run the specific reg through the free MOT history check.
  • Read the advisories. Repeated notes for the same component across years mean the owner has been ignoring it. Decode them in our advisory library.
  • Scan before you pay. A 2-minute OBD scan reveals stored faults the dashboard hides — see our scanner guide.

FAQs

Which A years should I avoid?

No year is a clear negative outlier after correcting for age, so buy on condition and history rather than year.

What is the best A year to buy used?

2021 and 2022 lead the age-adjusted MOT ranking. The score compares each registration year with all UK cars of the same age; the specific car's history and condition still take priority.

Is the A reliable overall?

Across 253,435 tests, the median age-adjusted index is 100.6 (100 equals the pass rate of all cars registered in the same year). Use the spread between years as one signal, then check the individual registration.

Methodology: index = 100 + the model-year cohort’s MOT pass-rate difference versus all UK vehicles registered in the same year and tested in the same calendar year. Class 4 initial tests only; retests excluded; at least 1,500 tests per page. “Inspect” years are below both the same-age baseline and the model’s median index by at least 2 points. Association is not proof of a model-year defect. DVSA anonymised data 2023–2025, OGL v3.0.