Mercedes-Benz Amg A 45 S 4Matic+ MOT pass rate & common failures
Across 5 model years and 2,927 tests, the Mercedes-Benz Amg A 45 S 4Matic+ passes its MOT 89.8% of the time. That is 1.2 percentage points worse than all cars of a similar age, which fail at 9.0%. Its most common failure areas are tyres, emissions & environmental and visibility.
What the MOT record shows
One area stands out: tyres, recorded in 7.5% of tests against 1.5% for the next-worst category.
At component level the recurring items are catalyst emissions, headlamp aim and tread depth — catalyst emissions alone was recorded 51 times.
Mileage matters less than usual here: the Amg A 45 S 4Matic+ fails 9.4% of the time in the 0-30k band and 10.0% at 60-90k, a spread of only 0.6 points.
Tyres is the most common advisory, noted on 15.6% of tests — work that passed today but is likely due soon.
How it compares
By model year
Every Amg A 45 S 4Matic+ model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 2019 | 90 | 85.6% | 14.4% | Tyres |
| 2020 | 1,920 | 89.3% | 10.7% | Tyres |
| 2021 | 635 | 90.5% | 9.4% | Tyres |
| 2022 | 253 | 92.9% | 7.1% | Tyres |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 7.5% | 221 |
| 2 | Emissions & environmental | 1.5% | 45 |
| 3 | Visibility | 1.0% | 28 |
| 4 | Lighting & signalling | 0.9% | 25 |
| 5 | Suspension | 0.5% | 16 |
| 6 | Other defects | 0.5% | 14 |
| 7 | Brakes | 0.5% | 14 |
| 8 | Road wheels | 0.2% | 7 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Catalyst emissions | 51 |
| 2 | Headlamp aim | 31 |
| 3 | Tread depth | 29 |
| 4 | Registration plates | 22 |
| 5 | Wipers | 19 |
| 6 | Washers | 10 |
| 7 | Pins and bushes | 6 |
| 8 | Brake pads | 6 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 15.6% | 457 |
| 2 | Brakes | 5.6% | 165 |
| 3 | Other defects | 3.7% | 109 |
| 4 | Visibility | 3.4% | 100 |
| 5 | Suspension | 0.9% | 27 |
| 6 | Road wheels | 0.9% | 26 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 1,931 | 9.4% |
| 30-60k | 913 | 12.0% |
| 60-90k | 80 | 10.0% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2022 | 64 | 10.9% |
| 2023 | 693 | 11.7% |
| 2024 | 949 | 10.1% |
| 2025 | 1,221 | 9.5% |
What to check before buying a Mercedes-Benz Amg A 45 S 4Matic+
- Tyres (7.5% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Emissions & environmental (1.5% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Visibility (1.0% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
What is the MOT pass rate for the Mercedes-Benz Amg A 45 S 4Matic+?
89.8% of the 2,927 Mercedes-Benz Amg A 45 S 4Matic+ MOT tests in this dataset passed, a 10.3% fail rate, across model years 2019–2023.
What does the Mercedes-Benz Amg A 45 S 4Matic+ most often fail its MOT on?
Tyres, recorded in 7.5% of tests, then emissions & environmental (1.5%).
How much does mileage affect Amg A 45 S 4Matic+ MOT results?
Fail rates run at 9.4% for cars in the 0-30k band and 10.0% for 60-90k, a 0.6-point difference.
Methodology & source. Based on 2,927 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.