2015 Mercedes-Benz A-Class — MOT failures & pass rate
Across 158,855 MOT tests, the 2015 Mercedes-Benz A-Class recorded an 84.0% pass rate. That is effectively the same as small family cars of a similar age (15.6% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in tyres, lighting & signalling and suspension.
What the MOT record shows
No single area dominates — tyres (7.3%) and lighting & signalling (5.4%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are tread depth, coil spring and brake pads — tread depth alone was recorded 5,311 times.
Mileage is the strongest signal on the record: 8.9% of 0-30k cars fail, rising to 20.7% once past 150k — 2.3× the risk.
The petrol cars hold up better: 13.1% fail against 16.6% for diesel, a 3.5-point gap across 158,855 tests.
Tyres is the most common advisory, noted on 27.6% of tests — work that passed today but is likely due soon.
The trend is worsening — 12.8% of tests failed in 2021 against 18.9% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 7.3% | 11,529 |
| 2 | Lighting & signalling | 5.4% | 8,644 |
| 3 | Suspension | 4.5% | 7,092 |
| 4 | Brakes | 3.2% | 5,073 |
| 5 | Visibility | 2.9% | 4,643 |
| 6 | Seat belts & restraints | 2.2% | 3,547 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 5,311 |
| 2 | Coil spring | 3,993 |
| 3 | Brake pads | 3,897 |
| 4 | Headlamp aim | 3,588 |
| 5 | Washers | 3,460 |
| 6 | SRS malfunction indicator lamp | 3,273 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 27.6% | 43,833 |
| 2 | Brakes | 19.7% | 31,332 |
| 3 | Other defects | 6.9% | 11,020 |
| 4 | Suspension | 5.8% | 9,152 |
| 5 | Visibility | 3.6% | 5,751 |
| 6 | Lighting & signalling | 1.5% | 2,368 |
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 | 8,538 | 8.9% |
| 30-60k | 56,413 | 13.1% |
| 60-90k | 59,997 | 17.3% |
| 90-120k | 25,257 | 20.3% |
| 120-150k | 6,740 | 20.9% |
| 150k+ | 1,861 | 20.7% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 131,809 | 16.6% |
| Petrol | 27,046 | 13.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 31,120 | 12.8% |
| 2022 | 31,589 | 14.5% |
| 2023 | 31,866 | 16.3% |
| 2024 | 32,106 | 17.6% |
| 2025 | 32,174 | 18.9% |
What to check before buying a 2015 A-Class
The failure pattern for this year is specific enough to inspect against: tyres accounted for 7.3% of tests. Start there.
- Tyres (7.3% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Lighting & signalling (5.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (4.5% 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.
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 2015 Mercedes-Benz A-Classs pass their MOT?
84.0% of the 158,855 2015 Mercedes-Benz A-Class MOT tests in this dataset passed — a 16.0% fail rate.
What is the most common MOT failure on a 2015 Mercedes-Benz A-Class?
Tyres, recorded in 7.3% of tests, followed by lighting & signalling (5.4%).
Does the 2015 A-Class get worse with mileage?
Its MOT fail rate rises from 8.9% in the 0-30k band to 20.7% in the 150k+ band.
Methodology & source. Based on 158,855 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.