2021 Mercedes-Benz Amg Cla 35 4Matic — MOT failures & pass rate
407 MOT tests on the 2021 Mercedes-Benz Amg Cla 35 4Matic are in this dataset, and 89.4% of them passed. Against all cars of a similar age (8.6% fail rate), the 2021 Amg Cla 35 4Matic comes out 1.9pp worse. Failures cluster in tyres, suspension and emissions & environmental.
What the MOT record shows
Tyres dominates the failure mix at 7.9% of all tests — 6.1 points clear of suspension, so it is the first thing to check.
At component level the recurring items are tread depth, catalyst emissions and pins and bushes — tread depth alone was recorded 8 times.
Advisories point at the next bill rather than this one: tyres was flagged on 22.4% of tests without failing them.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 7.9% | 32 |
| 2 | Suspension | 1.7% | 7 |
| 3 | Emissions & environmental | 1.2% | 5 |
| 4 | Brakes | 1.0% | 4 |
| 5 | Visibility | 0.5% | 2 |
| 6 | Road wheels | 0.5% | 2 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 8 |
| 2 | Catalyst emissions | 3 |
| 3 | Pins and bushes | 3 |
| 4 | Brake pads | 3 |
| 5 | Headlamp aim | 2 |
| 6 | Malfunction indicator lamp | 2 |
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 | 22.4% | 91 |
| 2 | Brakes | 6.9% | 28 |
| 3 | Other defects | 5.7% | 23 |
| 4 | Visibility | 3.4% | 14 |
| 5 | Suspension | 1.7% | 7 |
| 6 | Lighting & signalling | 0.7% | 3 |
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 | 244 | 8.6% |
| 30-60k | 153 | 14.4% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2024 | 190 | 10.0% |
| 2025 | 206 | 11.2% |
What to check before buying a 2021 Amg Cla 35 4Matic
On a 2021 Amg Cla 35 4Matic, tyres is what the MOT record says goes wrong most — it appeared in 7.9% of tests. Check these areas before you commit.
- Tyres (7.9% 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.
- Suspension (1.7% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Emissions & environmental (1.2% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 2021 Mercedes-Benz Amg Cla 35 4Matics pass their MOT?
89.4% of the 407 2021 Mercedes-Benz Amg Cla 35 4Matic MOT tests in this dataset passed — a 10.6% fail rate.
What is the most common MOT failure on a 2021 Mercedes-Benz Amg Cla 35 4Matic?
Tyres, recorded in 7.9% of tests, followed by suspension (1.7%).
Does the 2021 Amg Cla 35 4Matic get worse with mileage?
Its MOT fail rate rises from 8.6% in the 0-30k band to 14.4% in the 30-60k band.
Methodology & source. Based on 407 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.