2011 Mercedes-Benz B-Class — MOT failures & pass rate
23,983 MOT tests on the 2011 Mercedes-Benz B-Class are in this dataset, and 75.4% of them passed. MPVs of a similar age fail at 24.4%, so the 2011 B-Class sits squarely on the average. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
Lighting & signalling dominates the failure mix at 14.1% of all tests — 4.2 points clear of suspension, so it is the first thing to check.
At component level the recurring items are side repeaters, headlamp aim and individual direction indicators — side repeaters alone was recorded 1,341 times.
Condition tracks the odometer closely. Failures run at 13.7% in the 0-30k band and 31.6% in the 150k+ band, a 18.0-point spread — more than double.
Split by fuel, diesel examples fail 2.6pp more often than petrol ones (25.9% vs 23.3%) — worth weighing if you have a choice.
Advisories point at the next bill rather than this one: brakes was flagged on 32.6% of tests without failing them.
The trend is worsening — 22.7% of tests failed in 2021 against 25.8% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 14.1% | 3,379 |
| 2 | Suspension | 9.9% | 2,368 |
| 3 | Brakes | 8.3% | 1,993 |
| 4 | Tyres | 6.1% | 1,462 |
| 5 | Visibility | 4.2% | 995 |
| 6 | Emissions & environmental | 3.7% | 897 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Side repeaters | 1,341 |
| 2 | Headlamp aim | 1,053 |
| 3 | Individual direction indicators | 1,036 |
| 4 | Coil spring | 951 |
| 5 | Rigid brake pipes | 894 |
| 6 | Headlamp | 800 |
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 | 32.6% | 7,818 |
| 2 | Tyres | 26.6% | 6,371 |
| 3 | Suspension | 17.0% | 4,065 |
| 4 | Other defects | 15.4% | 3,688 |
| 5 | Lighting & signalling | 9.5% | 2,278 |
| 6 | Body, structure & corrosion | 5.9% | 1,410 |
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 | 658 | 13.7% |
| 30-60k | 5,887 | 20.2% |
| 60-90k | 9,651 | 24.8% |
| 90-120k | 5,838 | 28.2% |
| 120-150k | 1,509 | 28.9% |
| 150k+ | 433 | 31.6% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 12,214 | 23.3% |
| Diesel | 11,769 | 25.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 4,960 | 22.7% |
| 2022 | 4,930 | 23.3% |
| 2023 | 4,885 | 24.6% |
| 2024 | 4,768 | 26.5% |
| 2025 | 4,440 | 25.8% |
What to check before buying a 2011 B-Class
On a 2011 B-Class, lighting & signalling is what the MOT record says goes wrong most — it appeared in 14.1% of tests. Check these areas before you commit.
- Lighting & signalling (14.1% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (9.9% 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.
- Brakes (8.3% 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.
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 B-Classs pass their MOT?
75.4% of the 23,983 2011 Mercedes-Benz B-Class MOT tests in this dataset passed — a 24.6% fail rate.
What is the most common MOT failure on a 2011 Mercedes-Benz B-Class?
Lighting & signalling, recorded in 14.1% of tests, followed by suspension (9.9%).
Does the 2011 B-Class get worse with mileage?
Its MOT fail rate rises from 13.7% in the 0-30k band to 31.6% in the 150k+ band.
Methodology & source. Based on 23,983 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.