2015 Mercedes-Benz G-Class — MOT failures & pass rate
Across 892 MOT tests, the 2015 Mercedes-Benz G-Class recorded an 86.0% pass rate. That is effectively the same as large SUVs of a similar age (13.7% 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 (5.4%) 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 registration plates, headlamp aim and wipers — registration plates alone was recorded 31 times.
Mileage is the strongest signal on the record: 6.8% of 0-30k cars fail, rising to 15.2% once past 90-120k — 2.2× the risk.
Brakes is the most common advisory, noted on 13.1% of tests — work that passed today but is likely due soon.
The trend is worsening — 8.8% of tests failed in 2021 against 16.7% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 5.4% | 48 |
| 2 | Tyres | 4.3% | 38 |
| 3 | Brakes | 3.8% | 34 |
| 4 | Visibility | 2.9% | 26 |
| 5 | Emissions & environmental | 2.1% | 19 |
| 6 | Other defects | 1.9% | 17 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Registration plates | 31 |
| 2 | Headlamp aim | 26 |
| 3 | Wipers | 21 |
| 4 | Brake pads | 19 |
| 5 | Individual direction indicators | 13 |
| 6 | Rear fog lamp | 12 |
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 | 13.1% | 117 |
| 2 | Tyres | 10.8% | 96 |
| 3 | Emissions & environmental | 7.3% | 65 |
| 4 | Other defects | 5.2% | 46 |
| 5 | Visibility | 5.0% | 45 |
| 6 | Lighting & signalling | 4.9% | 44 |
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 | 177 | 6.8% |
| 30-60k | 469 | 16.2% |
| 60-90k | 203 | 14.8% |
| 90-120k | 33 | 15.2% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 524 | 13.7% |
| Diesel | 368 | 14.4% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 182 | 8.8% |
| 2022 | 172 | 11.6% |
| 2023 | 179 | 15.6% |
| 2024 | 179 | 17.3% |
| 2025 | 180 | 16.7% |
What to check before buying a 2015 G-Class
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 5.4% of tests. Start there.
- Lighting & signalling (5.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- 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.
- Brakes (3.8% 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.
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 G-Classs pass their MOT?
86.0% of the 892 2015 Mercedes-Benz G-Class MOT tests in this dataset passed — a 14.0% fail rate.
What is the most common MOT failure on a 2015 Mercedes-Benz G-Class?
Lighting & signalling, recorded in 5.4% of tests, followed by tyres (4.3%).
Does the 2015 G-Class get worse with mileage?
Its MOT fail rate rises from 6.8% in the 0-30k band to 15.2% in the 90-120k band.
Methodology & source. Based on 892 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.