2017 Mercedes-Benz A-Class — MOT failures & pass rate
The 2017 Mercedes-Benz A-Class passed 87.5% of its 232,506 recorded MOT tests. That is effectively the same as small family cars of a similar age (11.9% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in tyres, lighting & signalling and visibility.
What the MOT record shows
One area stands out: tyres, recorded in 7.0% of tests against 2.9% for the next-worst category.
At component level the recurring items are tread depth, washers and brake pads — tread depth alone was recorded 6,489 times.
A 150k+ example is materially riskier than a 0-30k one: 16.7% versus 7.7%.
The petrol cars hold up better: 10.8% fail against 13.3% for diesel, a 2.5-point gap across 232,506 tests.
Tyres is the most common advisory, noted on 26.4% of tests — work that passed today but is likely due soon.
The trend is worsening — 9.4% of tests failed in 2021 against 15.8% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 7.0% | 16,290 |
| 2 | Lighting & signalling | 2.9% | 6,680 |
| 3 | Visibility | 2.9% | 6,643 |
| 4 | Brakes | 2.4% | 5,538 |
| 5 | Suspension | 2.0% | 4,647 |
| 6 | Emissions & environmental | 1.2% | 2,807 |
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 | 6,489 |
| 2 | Washers | 4,671 |
| 3 | Brake pads | 4,626 |
| 4 | Headlamp aim | 4,291 |
| 5 | Coil spring | 3,091 |
| 6 | Wipers | 2,808 |
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 | 26.4% | 61,271 |
| 2 | Brakes | 16.4% | 38,081 |
| 3 | Other defects | 6.1% | 14,182 |
| 4 | Visibility | 3.0% | 7,071 |
| 5 | Suspension | 2.2% | 5,086 |
| 6 | Road wheels | 1.4% | 3,142 |
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 | 43,932 | 7.7% |
| 30-60k | 118,551 | 11.8% |
| 60-90k | 54,849 | 16.2% |
| 90-120k | 12,329 | 18.7% |
| 120-150k | 2,260 | 20.3% |
| 150k+ | 546 | 16.7% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 161,439 | 13.3% |
| Petrol | 71,067 | 10.8% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 45,556 | 9.4% |
| 2022 | 45,840 | 10.6% |
| 2023 | 46,571 | 12.5% |
| 2024 | 46,874 | 14.2% |
| 2025 | 47,665 | 15.8% |
What to check before buying a 2017 A-Class
The failure pattern for this year is specific enough to inspect against: tyres accounted for 7.0% of tests. Start there.
- Tyres (7.0% 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 (2.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (2.9% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
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 2017 Mercedes-Benz A-Classs pass their MOT?
87.5% of the 232,506 2017 Mercedes-Benz A-Class MOT tests in this dataset passed — a 12.5% fail rate.
What is the most common MOT failure on a 2017 Mercedes-Benz A-Class?
Tyres, recorded in 7.0% of tests, followed by lighting & signalling (2.9%).
Does the 2017 A-Class get worse with mileage?
Its MOT fail rate rises from 7.7% in the 0-30k band to 16.7% in the 150k+ band.
Methodology & source. Based on 232,506 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.