2017 Mercedes-Benz G-Class — MOT failures & pass rate
1,296 MOT tests on the 2017 Mercedes-Benz G-Class are in this dataset, and 88.0% of them passed. That is effectively the same as large SUVs of a similar age (11.4% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in lighting & signalling, tyres and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (4.4%) and tyres (3.3%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, registration plates and coil spring — headlamp aim alone was recorded 46 times.
Mileage is the strongest signal on the record: 10.3% of 0-30k cars fail, rising to 19.4% once past 90-120k.
Fuel type barely separates them — petrol fails 11.8% of the time against 12.3% for diesel.
Brakes is the most common advisory, noted on 12.3% of tests — work that passed today but is likely due soon.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 4.4% | 57 |
| 2 | Tyres | 3.3% | 43 |
| 3 | Brakes | 2.9% | 38 |
| 4 | Suspension | 2.1% | 27 |
| 5 | Steering | 1.5% | 20 |
| 6 | Emissions & environmental | 1.4% | 18 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 46 |
| 2 | Registration plates | 31 |
| 3 | Coil spring | 29 |
| 4 | Brake pads | 18 |
| 5 | Wipers | 17 |
| 6 | Brake discs | 13 |
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 | 12.3% | 160 |
| 2 | Tyres | 11.9% | 154 |
| 3 | Steering | 6.2% | 80 |
| 4 | Other defects | 4.2% | 55 |
| 5 | Visibility | 3.9% | 50 |
| 6 | Emissions & environmental | 3.3% | 43 |
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 | 556 | 10.3% |
| 30-60k | 570 | 13.7% |
| 60-90k | 130 | 10.8% |
| 90-120k | 36 | 19.4% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 735 | 11.8% |
| Diesel | 561 | 12.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 266 | 12.8% |
| 2022 | 230 | 7.8% |
| 2023 | 259 | 12.4% |
| 2024 | 272 | 15.1% |
| 2025 | 269 | 11.5% |
What to check before buying a 2017 G-Class
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 4.4% of tests. Start there.
- Lighting & signalling (4.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (3.3% 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.
- Brakes (2.9% 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.
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 G-Classs pass their MOT?
88.0% of the 1,296 2017 Mercedes-Benz G-Class MOT tests in this dataset passed — a 12.0% fail rate.
What is the most common MOT failure on a 2017 Mercedes-Benz G-Class?
Lighting & signalling, recorded in 4.4% of tests, followed by tyres (3.3%).
Does the 2017 G-Class get worse with mileage?
Its MOT fail rate rises from 10.3% in the 0-30k band to 19.4% in the 90-120k band.
Methodology & source. Based on 1,296 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.