2015 Mercedes-Benz Ml — MOT failures & pass rate
The 2015 Mercedes-Benz Ml passed 88.3% of its 17,991 recorded MOT tests. Against large SUVs of a similar age (13.7% fail rate), the 2015 Ml comes out 2.0pp better. Failures cluster in tyres, lighting & signalling and suspension.
What the MOT record shows
No single area dominates — tyres (5.6%) and lighting & signalling (3.0%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are coil spring, tread depth and headlamp aim — coil spring alone was recorded 490 times.
Mileage is the strongest signal on the record: 7.6% of 0-30k cars fail, rising to 19.4% once past 150k — 2.5× the risk.
Advisories point at the next bill rather than this one: tyres was flagged on 23.1% of tests without failing them.
The trend is worsening — 10.2% of tests failed in 2021 against 13.1% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.6% | 1,007 |
| 2 | Lighting & signalling | 3.0% | 547 |
| 3 | Suspension | 2.8% | 501 |
| 4 | Emissions & environmental | 1.9% | 348 |
| 5 | Brakes | 1.7% | 306 |
| 6 | Visibility | 1.2% | 208 |
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 | 490 |
| 2 | Tread depth | 465 |
| 3 | Headlamp aim | 340 |
| 4 | Malfunction indicator lamp | 338 |
| 5 | Brake pads | 274 |
| 6 | Washers | 135 |
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 | 23.1% | 4,150 |
| 2 | Brakes | 13.4% | 2,408 |
| 3 | Other defects | 6.5% | 1,173 |
| 4 | Visibility | 3.4% | 613 |
| 5 | Suspension | 2.4% | 422 |
| 6 | Body, structure & corrosion | 1.5% | 273 |
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 | 772 | 7.6% |
| 30-60k | 6,424 | 9.8% |
| 60-90k | 6,969 | 12.0% |
| 90-120k | 2,843 | 14.5% |
| 120-150k | 742 | 15.6% |
| 150k+ | 237 | 19.4% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 17,628 | 11.7% |
| Petrol | 363 | 8.5% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,673 | 10.2% |
| 2022 | 3,579 | 10.5% |
| 2023 | 3,583 | 11.4% |
| 2024 | 3,607 | 13.3% |
| 2025 | 3,549 | 13.1% |
What to check before buying a 2015 Ml
On a 2015 Ml, tyres is what the MOT record says goes wrong most — it appeared in 5.6% of tests. Check these areas before you commit.
- Tyres (5.6% 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 (3.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (2.8% 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 Mls pass their MOT?
88.3% of the 17,991 2015 Mercedes-Benz Ml MOT tests in this dataset passed — a 11.7% fail rate.
What is the most common MOT failure on a 2015 Mercedes-Benz Ml?
Tyres, recorded in 5.6% of tests, followed by lighting & signalling (3.0%).
Does the 2015 Ml get worse with mileage?
Its MOT fail rate rises from 7.6% in the 0-30k band to 19.4% in the 150k+ band.
Methodology & source. Based on 17,991 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.