2020 Mercedes-Benz X — MOT failures & pass rate
Across 2,158 MOT tests, the 2020 Mercedes-Benz X recorded an 87.7% pass rate. Against all cars of a similar age (9.4% fail rate), the 2020 X comes out 3.0pp worse. Failures cluster in brakes, tyres and visibility.
What the MOT record shows
No single area dominates — brakes (4.8%) and tyres (3.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are wipers, malfunction indicator lamp and brake pads — wipers alone was recorded 59 times.
Condition tracks the odometer closely. Failures run at 10.6% in the 0-30k band and 16.5% in the 90-120k band, a 5.9-point spread.
Tyres is the most common advisory, noted on 13.8% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 13.5% in 2023 to 10.3% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Brakes | 4.8% | 104 |
| 2 | Tyres | 3.1% | 68 |
| 3 | Visibility | 3.0% | 65 |
| 4 | Lighting & signalling | 2.7% | 59 |
| 5 | Emissions & environmental | 2.5% | 55 |
| 6 | Seat belts & restraints | 1.5% | 32 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Wipers | 59 |
| 2 | Malfunction indicator lamp | 52 |
| 3 | Brake pads | 47 |
| 4 | Rbt (sp) | 35 |
| 5 | SRS malfunction indicator lamp | 29 |
| 6 | Tread depth | 25 |
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 | 13.8% | 298 |
| 2 | Brakes | 12.5% | 269 |
| 3 | Visibility | 5.9% | 128 |
| 4 | Lighting & signalling | 4.4% | 94 |
| 5 | Other defects | 4.4% | 94 |
| 6 | Suspension | 2.4% | 51 |
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 | 547 | 10.6% |
| 30-60k | 1,039 | 12.0% |
| 60-90k | 421 | 13.8% |
| 90-120k | 115 | 16.5% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 694 | 13.5% |
| 2024 | 729 | 13.0% |
| 2025 | 721 | 10.3% |
What to check before buying a 2020 X
The failure pattern for this year is specific enough to inspect against: brakes accounted for 4.8% of tests. Start there.
- Brakes (4.8% 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 (3.1% 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.
- Visibility (3.0% 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 2020 Mercedes-Benz Xs pass their MOT?
87.7% of the 2,158 2020 Mercedes-Benz X MOT tests in this dataset passed — a 12.3% fail rate.
What is the most common MOT failure on a 2020 Mercedes-Benz X?
Brakes, recorded in 4.8% of tests, followed by tyres (3.1%).
Does the 2020 X get worse with mileage?
Its MOT fail rate rises from 10.6% in the 0-30k band to 16.5% in the 90-120k band.
Methodology & source. Based on 2,158 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.