2012 Mercedes-Benz Gl — MOT failures & pass rate
The 2012 Mercedes-Benz Gl passed 87.1% of its 572 recorded MOT tests. That is 4.9 percentage points better than large SUVs of a similar age, which fail at 17.8%. Failures cluster in lighting & signalling, tyres and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (4.9%) and tyres (4.2%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are position lamp, rigid brake pipes and malfunction indicator lamp — position lamp alone was recorded 14 times.
A 150k+ example is materially riskier than a 30-60k one: 7.8% versus 3.4%.
Brakes is the most common advisory, noted on 20.4% 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 | 4.9% | 28 |
| 2 | Tyres | 4.2% | 24 |
| 3 | Brakes | 3.7% | 21 |
| 4 | Emissions & environmental | 2.5% | 14 |
| 5 | Suspension | 1.4% | 8 |
| 6 | Body, structure & corrosion | 1.1% | 6 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Position lamp | 14 |
| 2 | Rigid brake pipes | 13 |
| 3 | Malfunction indicator lamp | 13 |
| 4 | Headlamp aim | 12 |
| 5 | Tread depth | 11 |
| 6 | Shock absorbers | 5 |
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 | 20.4% | 117 |
| 2 | Tyres | 19.9% | 114 |
| 3 | Emissions & environmental | 14.0% | 80 |
| 4 | Suspension | 10.3% | 59 |
| 5 | Other defects | 5.8% | 33 |
| 6 | Visibility | 4.7% | 27 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 59 | 3.4% |
| 60-90k | 182 | 15.4% |
| 90-120k | 179 | 15.6% |
| 120-150k | 94 | 12.8% |
| 150k+ | 51 | 7.8% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 531 | 13.0% |
| Petrol | 41 | 12.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 120 | 13.3% |
| 2022 | 111 | 7.2% |
| 2023 | 128 | 19.5% |
| 2024 | 104 | 11.5% |
| 2025 | 109 | 11.9% |
What to check before buying a 2012 Gl
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 4.9% of tests. Start there.
- Lighting & signalling (4.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (4.2% 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 (3.7% 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 2012 Mercedes-Benz Gls pass their MOT?
87.1% of the 572 2012 Mercedes-Benz Gl MOT tests in this dataset passed — a 12.9% fail rate.
What is the most common MOT failure on a 2012 Mercedes-Benz Gl?
Lighting & signalling, recorded in 4.9% of tests, followed by tyres (4.2%).
Does the 2012 Gl get worse with mileage?
Its MOT fail rate rises from 3.4% in the 30-60k band to 7.8% in the 150k+ band.
Methodology & source. Based on 572 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.