2005 Mercedes-Benz A-Class — MOT failures & pass rate
Across 23,999 MOT tests analysed for the 2005 Mercedes-Benz A-Class, the most common recorded failure areas were lighting & signalling, suspension and brakes. Its pass rate of 74.3% was above the average for small family cars of a similar age (72.1%). Higher-mileage examples failed more often — 33.5% in the 150k+ group versus 19.6% in the 0-30k group.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 14.6% | 3,501 |
| 2 | Suspension | 9.3% | 2,234 |
| 3 | Brakes | 8.2% | 1,978 |
| 4 | Body, structure & corrosion | 8.1% | 1,947 |
| 5 | Visibility | 8.0% | 1,927 |
| 6 | Emissions & environmental | 4.8% | 1,161 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Joints | 1,926 |
| 2 | Headlamp aim | 1,741 |
| 3 | Washers | 1,620 |
| 4 | Coil spring | 1,432 |
| 5 | Stop lamp | 1,095 |
| 6 | Headlamp | 933 |
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 | 36.1% | 8,666 |
| 2 | Tyres | 28.5% | 6,839 |
| 3 | Suspension | 19.4% | 4,661 |
| 4 | Other defects | 15.0% | 3,594 |
| 5 | Body, structure & corrosion | 12.2% | 2,935 |
| 6 | Lighting & signalling | 11.8% | 2,841 |
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 | 782 | 19.6% |
| 30-60k | 4,193 | 18.4% |
| 60-90k | 8,344 | 25.3% |
| 90-120k | 6,790 | 28.1% |
| 120-150k | 2,553 | 30.2% |
| 150k+ | 878 | 33.5% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 17,265 | 24.4% |
| Diesel | 6,734 | 29.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 6,688 | 26.0% |
| 2022 | 5,628 | 25.6% |
| 2023 | 4,769 | 26.0% |
| 2024 | 3,848 | 25.7% |
| 2025 | 3,066 | 25.2% |
What to check before buying a 2005 A-Class
Before buying a 2005 Mercedes-Benz A-Class, focus on the areas it most often fails on. Lighting & signalling accounted for 14.6% of tests for this year.
- Lighting & signalling (14.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (9.3% 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 (8.2% 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 A-Classs pass their MOT?
74.3% of the 23,999 2005 Mercedes-Benz A-Class MOT tests in this dataset passed — a 25.7% fail rate.
What is the most common MOT failure on a 2005 Mercedes-Benz A-Class?
Lighting & signalling, recorded in 14.6% of tests, followed by suspension (9.3%).
Does the 2005 A-Class get worse with mileage?
Its MOT fail rate rises from 19.6% in the 0-30k band to 33.5% in the 150k+ band.
Methodology & source. Based on 23,999 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.