2009 Mercedes-Benz Gl 320 — MOT failures & pass rate
Across 506 MOT tests, the 2009 Mercedes-Benz Gl 320 recorded an 80.0% pass rate. All cars of a similar age fail 25.4% of the time, so this is 5.4pp better than the group it competes with. Failures cluster in lighting & signalling, brakes and emissions & environmental.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 16.4% of tests against 6.1% for the next-worst category.
At component level the recurring items are side repeaters, individual direction indicators and position lamp — side repeaters alone was recorded 37 times.
A 150k+ example is materially riskier than a 60-90k one: 12.6% versus 22.7%.
Brakes is the most common advisory, noted on 33.4% 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 | 16.4% | 83 |
| 2 | Brakes | 6.1% | 31 |
| 3 | Emissions & environmental | 4.9% | 25 |
| 4 | Tyres | 4.5% | 23 |
| 5 | Suspension | 3.2% | 16 |
| 6 | Body, structure & corrosion | 2.8% | 14 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Side repeaters | 37 |
| 2 | Individual direction indicators | 24 |
| 3 | Position lamp | 23 |
| 4 | On or after 01/07/2008 | 19 |
| 5 | Rigid brake pipes | 19 |
| 6 | Tread depth | 18 |
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 | 33.4% | 169 |
| 2 | Emissions & environmental | 25.9% | 131 |
| 3 | Tyres | 24.7% | 125 |
| 4 | Suspension | 21.3% | 108 |
| 5 | Lighting & signalling | 10.9% | 55 |
| 6 | Other defects | 6.5% | 33 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 60-90k | 110 | 22.7% |
| 90-120k | 164 | 26.8% |
| 120-150k | 119 | 13.5% |
| 150k+ | 95 | 12.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 119 | 18.5% |
| 2022 | 107 | 19.6% |
| 2023 | 96 | 20.8% |
| 2024 | 98 | 23.5% |
| 2025 | 86 | 17.4% |
What to check before buying a 2009 Gl 320
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 16.4% of tests. Start there.
- Lighting & signalling (16.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (6.1% 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.
- Emissions & environmental (4.9% 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 2009 Mercedes-Benz Gl 320s pass their MOT?
80.0% of the 506 2009 Mercedes-Benz Gl 320 MOT tests in this dataset passed — a 20.0% fail rate.
What is the most common MOT failure on a 2009 Mercedes-Benz Gl 320?
Lighting & signalling, recorded in 16.4% of tests, followed by brakes (6.1%).
Does the 2009 Gl 320 get worse with mileage?
Its MOT fail rate rises from 22.7% in the 60-90k band to 12.6% in the 150k+ band.
Methodology & source. Based on 506 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.