2010 Mercedes-Benz B-Class — MOT failures & pass rate
The 2010 Mercedes-Benz B-Class passed 75.1% of its 31,153 recorded MOT tests. That is 1.0 percentage points better than MPVs of a similar age, which fail at 25.9%. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 14.1% of tests against 10.5% for the next-worst category.
At component level the recurring items are headlamp aim, side repeaters and rigid brake pipes — headlamp aim alone was recorded 1,464 times.
Mileage is the strongest signal on the record: 12.9% of 0-30k cars fail, rising to 30.4% once past 150k — 2.4× the risk.
The petrol cars hold up better: 23.5% fail against 26.3% for diesel, a 2.8-point gap across 31,153 tests.
Brakes is the most common advisory, noted on 34.7% of tests — work that passed today but is likely due soon.
The trend is worsening — 22.6% of tests failed in 2021 against 26.3% 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% | 4,404 |
| 2 | Suspension | 10.5% | 3,270 |
| 3 | Brakes | 9.0% | 2,793 |
| 4 | Tyres | 5.2% | 1,609 |
| 5 | Body, structure & corrosion | 4.8% | 1,482 |
| 6 | Visibility | 4.4% | 1,369 |
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 | 1,464 |
| 2 | Side repeaters | 1,460 |
| 3 | Rigid brake pipes | 1,442 |
| 4 | Individual direction indicators | 1,371 |
| 5 | Coil spring | 1,346 |
| 6 | Ball joint | 1,189 |
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 | 34.7% | 10,800 |
| 2 | Tyres | 27.0% | 8,414 |
| 3 | Suspension | 17.6% | 5,475 |
| 4 | Other defects | 15.7% | 4,890 |
| 5 | Lighting & signalling | 8.9% | 2,786 |
| 6 | Body, structure & corrosion | 8.9% | 2,778 |
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 | 635 | 12.9% |
| 30-60k | 5,818 | 18.7% |
| 60-90k | 12,264 | 24.3% |
| 90-120k | 8,382 | 28.4% |
| 120-150k | 3,009 | 29.8% |
| 150k+ | 1,031 | 30.4% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 16,061 | 23.5% |
| Diesel | 15,092 | 26.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 6,484 | 22.6% |
| 2022 | 6,516 | 24.0% |
| 2023 | 6,358 | 25.1% |
| 2024 | 6,122 | 26.6% |
| 2025 | 5,673 | 26.3% |
What to check before buying a 2010 B-Class
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 14.1% of tests. Start there.
- 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 (10.5% 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 (9.0% 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.
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 2010 Mercedes-Benz B-Classs pass their MOT?
75.1% of the 31,153 2010 Mercedes-Benz B-Class MOT tests in this dataset passed — a 24.9% fail rate.
What is the most common MOT failure on a 2010 Mercedes-Benz B-Class?
Lighting & signalling, recorded in 14.1% of tests, followed by suspension (10.5%).
Does the 2010 B-Class get worse with mileage?
Its MOT fail rate rises from 12.9% in the 0-30k band to 30.4% in the 150k+ band.
Methodology & source. Based on 31,153 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.