2011 Mercedes-Benz A-Class — MOT failures & pass rate
The 2011 Mercedes-Benz A-Class passed 79.7% of its 34,761 recorded MOT tests. Small family cars of a similar age fail 22.9% of the time, so this is 2.6pp better than the group it competes with. Failures cluster in lighting & signalling, brakes and suspension.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 11.9% of tests against 7.0% for the next-worst category.
At component level the recurring items are headlamp aim, side repeaters and washers — headlamp aim alone was recorded 1,875 times.
A 150k+ example is materially riskier than a 0-30k one: 31.4% versus 12.8%.
Fuel type barely separates them — petrol fails 19.9% of the time against 21.2% for diesel.
Brakes is the most common advisory, noted on 30.3% of tests — work that passed today but is likely due soon.
The trend is worsening — 18.1% of tests failed in 2021 against 22.2% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 11.9% | 4,139 |
| 2 | Brakes | 7.0% | 2,438 |
| 3 | Suspension | 5.7% | 1,991 |
| 4 | Visibility | 4.7% | 1,649 |
| 5 | Tyres | 3.5% | 1,218 |
| 6 | Emissions & environmental | 2.7% | 947 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 1,875 |
| 2 | Side repeaters | 1,551 |
| 3 | Washers | 1,295 |
| 4 | Rigid brake pipes | 1,167 |
| 5 | Coil spring | 1,014 |
| 6 | Headlamp | 873 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 30.3% | 10,540 |
| 2 | Tyres | 25.3% | 8,779 |
| 3 | Other defects | 10.7% | 3,728 |
| 4 | Suspension | 9.4% | 3,256 |
| 5 | Body, structure & corrosion | 4.6% | 1,596 |
| 6 | Visibility | 3.9% | 1,366 |
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 | 2,285 | 12.8% |
| 30-60k | 12,490 | 16.9% |
| 60-90k | 12,495 | 21.6% |
| 90-120k | 5,557 | 25.2% |
| 120-150k | 1,521 | 28.1% |
| 150k+ | 407 | 31.4% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 22,548 | 19.9% |
| Diesel | 12,213 | 21.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 7,069 | 18.1% |
| 2022 | 7,076 | 19.0% |
| 2023 | 7,052 | 20.3% |
| 2024 | 6,954 | 22.2% |
| 2025 | 6,610 | 22.2% |
What to check before buying a 2011 A-Class
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 11.9% of tests. Start there.
- Lighting & signalling (11.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (7.0% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
- Suspension (5.7% 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.
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 2011 Mercedes-Benz A-Classs pass their MOT?
79.7% of the 34,761 2011 Mercedes-Benz A-Class MOT tests in this dataset passed — a 20.3% fail rate.
What is the most common MOT failure on a 2011 Mercedes-Benz A-Class?
Lighting & signalling, recorded in 11.9% of tests, followed by brakes (7.0%).
Does the 2011 A-Class get worse with mileage?
Its MOT fail rate rises from 12.8% in the 0-30k band to 31.4% in the 150k+ band.
Methodology & source. Based on 34,761 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.