2017 Mercedes-Benz M8 — MOT failures & pass rate
632 MOT tests on the 2017 Mercedes-Benz M8 are in this dataset, and 75.5% of them passed. That is 11.9 percentage points worse than all cars of a similar age, which fail at 12.6%. Failures cluster in suspension, brakes and lighting & signalling.
What the MOT record shows
No single area dominates — suspension (12.0%) and brakes (9.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are ball joint, coil spring and service brake performance — ball joint alone was recorded 31 times.
Mileage matters less than usual here: the 2017 M8 fails 22.2% of the time in the 90-120k band and 26.1% at 150k+, a spread of only 3.8 points.
Advisories point at the next bill rather than this one: tyres was flagged on 14.6% of tests without failing them.
The trend is worsening — 17.8% of tests failed in 2021 against 27.9% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 12.0% | 76 |
| 2 | Brakes | 9.5% | 60 |
| 3 | Lighting & signalling | 5.2% | 33 |
| 4 | Emissions & environmental | 3.0% | 19 |
| 5 | Tyres | 2.7% | 17 |
| 6 | Visibility | 2.4% | 15 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Ball joint | 31 |
| 2 | Coil spring | 29 |
| 3 | Service brake performance | 27 |
| 4 | Rbt (sp) | 24 |
| 5 | Headlamp aim | 21 |
| 6 | Linkage ball joint dust cover | 18 |
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 | 14.6% | 92 |
| 2 | Suspension | 13.1% | 83 |
| 3 | Brakes | 12.8% | 81 |
| 4 | Other defects | 5.5% | 35 |
| 5 | Visibility | 3.6% | 23 |
| 6 | Emissions & environmental | 3.5% | 22 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 90-120k | 54 | 22.2% |
| 120-150k | 87 | 18.4% |
| 150k+ | 472 | 26.1% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 129 | 17.8% |
| 2022 | 128 | 25.8% |
| 2023 | 129 | 25.6% |
| 2024 | 124 | 25.8% |
| 2025 | 122 | 27.9% |
What to check before buying a 2017 M8
On a 2017 M8, suspension is what the MOT record says goes wrong most — it appeared in 12.0% of tests. Check these areas before you commit.
- Suspension (12.0% 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 (9.5% 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.
- Lighting & signalling (5.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£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 M8s pass their MOT?
75.5% of the 632 2017 Mercedes-Benz M8 MOT tests in this dataset passed — a 24.5% fail rate.
What is the most common MOT failure on a 2017 Mercedes-Benz M8?
Suspension, recorded in 12.0% of tests, followed by brakes (9.5%).
Does the 2017 M8 get worse with mileage?
Its MOT fail rate rises from 22.2% in the 90-120k band to 26.1% in the 150k+ band.
Methodology & source. Based on 632 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.