Mercedes-Benz M8 MOT pass rate & common failures
The Mercedes-Benz M8 appears in 1,484 MOT tests spanning model years 2016–2020, and 79.0% of them passed. All cars of a similar age fail 11.5% of the time, so this is 9.4pp worse than the group it competes with. Its most common failure areas are suspension, brakes and lighting & signalling.
What the MOT record shows
No single area dominates — suspension (9.6%) and brakes (7.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are coil spring, rbt (sp) and service brake performance — coil spring alone was recorded 56 times.
Mileage is the strongest signal on the record: 2.7% of 30-60k cars fail, rising to 25.2% once past 150k — 9.3× the risk.
Advisories point at the next bill rather than this one: tyres was flagged on 14.5% of tests without failing them.
The trend is worsening — 14.8% of tests failed in 2021 against 27.3% in 2025, the usual pattern as a fleet ages.
How it compares
By model year
Every M8 model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 2016 | 62 | 82.3% | 17.7% | Suspension |
| 2017 | 632 | 75.5% | 24.5% | Suspension |
| 2018 | 520 | 78.5% | 21.5% | Suspension |
| 2019 | 267 | 87.6% | 12.4% | Suspension |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 9.6% | 142 |
| 2 | Brakes | 7.5% | 111 |
| 3 | Lighting & signalling | 4.0% | 60 |
| 4 | Emissions & environmental | 3.0% | 44 |
| 5 | Tyres | 2.6% | 39 |
| 6 | Seat belts & restraints | 1.8% | 26 |
| 7 | Visibility | 1.5% | 22 |
| 8 | Body, structure & corrosion | 1.4% | 21 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Coil spring | 56 |
| 2 | Rbt (sp) | 49 |
| 3 | Service brake performance | 41 |
| 4 | Ball joint | 36 |
| 5 | Headlamp aim | 35 |
| 6 | Linkage ball joint dust cover | 33 |
| 7 | Linkage pins and bushes | 30 |
| 8 | Malfunction indicator lamp | 27 |
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 | 14.5% | 215 |
| 2 | Suspension | 11.9% | 176 |
| 3 | Brakes | 10.3% | 153 |
| 4 | Other defects | 4.7% | 70 |
| 5 | Emissions & environmental | 3.0% | 44 |
| 6 | Visibility | 2.2% | 32 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 37 | 2.7% |
| 60-90k | 117 | 11.1% |
| 90-120k | 193 | 16.1% |
| 120-150k | 225 | 16.4% |
| 150k+ | 908 | 25.2% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 303 | 14.8% |
| 2022 | 294 | 17.7% |
| 2023 | 306 | 22.9% |
| 2024 | 292 | 22.3% |
| 2025 | 289 | 27.3% |
What to check before buying a Mercedes-Benz M8
- Suspension (9.6% 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 (7.5% 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 (4.0% 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
What is the MOT pass rate for the Mercedes-Benz M8?
79.0% of the 1,484 Mercedes-Benz M8 MOT tests in this dataset passed, a 21.0% fail rate, across model years 2016–2020.
What does the Mercedes-Benz M8 most often fail its MOT on?
Suspension, recorded in 9.6% of tests, then brakes (7.5%).
How much does mileage affect M8 MOT results?
Fail rates run at 2.7% for cars in the 30-60k band and 25.2% for 150k+, a 22.5-point difference.
Methodology & source. Based on 1,484 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.