2005 Mercedes-Benz B-Class — MOT failures & pass rate
Across 3,546 MOT tests analysed for the 2005 Mercedes-Benz B-Class, the most common recorded failure areas were lighting & signalling, body, structure & corrosion and brakes. Its pass rate of 73.0% was above the average for MPVs of a similar age (69.6%). Higher-mileage examples failed more often — 31.7% in the 150k+ group versus 14.6% in the 0-30k group.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 14.0% | 496 |
| 2 | Body, structure & corrosion | 11.2% | 397 |
| 3 | Brakes | 10.8% | 383 |
| 4 | Suspension | 10.0% | 355 |
| 5 | Visibility | 7.0% | 250 |
| 6 | Emissions & environmental | 6.1% | 217 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Joints | 405 |
| 2 | Coil spring | 218 |
| 3 | Washers | 214 |
| 4 | Headlamp aim | 200 |
| 5 | Headlamp | 153 |
| 6 | Rbt (sp) | 136 |
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 | 40.0% | 1,418 |
| 2 | Tyres | 27.1% | 962 |
| 3 | Suspension | 20.5% | 726 |
| 4 | Other defects | 18.5% | 655 |
| 5 | Body, structure & corrosion | 17.0% | 602 |
| 6 | Lighting & signalling | 10.8% | 384 |
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 | 41 | 14.6% |
| 30-60k | 303 | 22.4% |
| 60-90k | 982 | 25.1% |
| 90-120k | 1,235 | 27.8% |
| 120-150k | 731 | 29.1% |
| 150k+ | 227 | 31.7% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 1,890 | 24.2% |
| Diesel | 1,656 | 30.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,022 | 26.1% |
| 2022 | 851 | 26.7% |
| 2023 | 712 | 28.5% |
| 2024 | 532 | 26.1% |
| 2025 | 429 | 28.7% |
What to check before buying a 2005 B-Class
Before buying a 2005 Mercedes-Benz B-Class, focus on the areas it most often fails on. Lighting & signalling accounted for 14.0% of tests for this year.
- Lighting & signalling (14.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Body, structure & corrosion (11.2% of tests): The one to take seriously on older cars — corrosion to structural areas can be costly and is an MOT failure. Typical repair: £200–£1,500+.
- Brakes (10.8% 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 2005 Mercedes-Benz B-Classs pass their MOT?
73.0% of the 3,546 2005 Mercedes-Benz B-Class MOT tests in this dataset passed — a 27.0% fail rate.
What is the most common MOT failure on a 2005 Mercedes-Benz B-Class?
Lighting & signalling, recorded in 14.0% of tests, followed by body, structure & corrosion (11.2%).
Does the 2005 B-Class get worse with mileage?
Its MOT fail rate rises from 14.6% in the 0-30k band to 31.7% in the 150k+ band.
Methodology & source. Based on 3,546 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.