2017 Mercedes-Benz X — MOT failures & pass rate
Across 882 MOT tests, the 2017 Mercedes-Benz X recorded an 84.6% pass rate. That is 2.7 percentage points worse than all cars of a similar age, which fail at 12.7%. Failures cluster in brakes, tyres and emissions & environmental.
What the MOT record shows
No single area dominates — brakes (4.3%) and tyres (4.3%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are malfunction indicator lamp, tread depth and wipers — malfunction indicator lamp alone was recorded 37 times.
Condition tracks the odometer closely. Failures run at 13.9% in the 0-30k band and 22.2% in the 120-150k band, a 8.4-point spread.
Brakes is the most common advisory, noted on 19.4% of tests — work that passed today but is likely due soon.
The trend is worsening — 11.5% of tests failed in 2021 against 16.3% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Brakes | 4.3% | 38 |
| 2 | Tyres | 4.3% | 38 |
| 3 | Emissions & environmental | 4.2% | 37 |
| 4 | Lighting & signalling | 3.6% | 32 |
| 5 | Visibility | 3.4% | 30 |
| 6 | Seat belts & restraints | 2.3% | 20 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Malfunction indicator lamp | 37 |
| 2 | Tread depth | 27 |
| 3 | Wipers | 23 |
| 4 | Brake pads | 20 |
| 5 | SRS malfunction indicator lamp | 17 |
| 6 | Headlamp aim | 14 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 19.4% | 171 |
| 2 | Tyres | 16.1% | 142 |
| 3 | Suspension | 6.3% | 56 |
| 4 | Emissions & environmental | 6.0% | 53 |
| 5 | Visibility | 5.8% | 51 |
| 6 | Lighting & signalling | 5.3% | 47 |
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 | 101 | 13.9% |
| 30-60k | 341 | 11.4% |
| 60-90k | 279 | 17.9% |
| 90-120k | 93 | 17.2% |
| 120-150k | 45 | 22.2% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 174 | 11.5% |
| 2022 | 184 | 17.9% |
| 2023 | 175 | 14.3% |
| 2024 | 171 | 17.0% |
| 2025 | 178 | 16.3% |
What to check before buying a 2017 X
The failure pattern for this year is specific enough to inspect against: brakes accounted for 4.3% of tests. Start there.
- Brakes (4.3% 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.
- Tyres (4.3% 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.
- Emissions & environmental (4.2% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
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 Xs pass their MOT?
84.6% of the 882 2017 Mercedes-Benz X MOT tests in this dataset passed — a 15.4% fail rate.
What is the most common MOT failure on a 2017 Mercedes-Benz X?
Brakes, recorded in 4.3% of tests, followed by tyres (4.3%).
Does the 2017 X get worse with mileage?
Its MOT fail rate rises from 13.9% in the 0-30k band to 22.2% in the 120-150k band.
Methodology & source. Based on 882 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.