2006 Mercedes-Benz Gl 320 — MOT failures & pass rate
267 MOT tests on the 2006 Mercedes-Benz Gl 320 are in this dataset, and 83.2% of them passed. Against all cars of a similar age (27.3% fail rate), the 2006 Gl 320 comes out 10.4pp better. Failures cluster in lighting & signalling, brakes and emissions & environmental.
What the MOT record shows
Lighting & signalling dominates the failure mix at 14.2% of all tests — 6.4 points clear of brakes, so it is the first thing to check.
At component level the recurring items are position lamp, rigid brake pipes and stop lamp — position lamp alone was recorded 15 times.
Mileage matters less than usual here: the 2006 Gl 320 fails 16.7% of the time in the 60-90k band and 13.2% at 150k+, a spread of only 3.5 points.
Advisories point at the next bill rather than this one: brakes was flagged on 28.1% of tests without failing them.
The trend is improving — the fail rate fell from 17.8% in 2021 to 12.1% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 14.2% | 38 |
| 2 | Brakes | 7.9% | 21 |
| 3 | Emissions & environmental | 5.6% | 15 |
| 4 | Suspension | 5.2% | 14 |
| 5 | Tyres | 3.8% | 10 |
| 6 | Visibility | 3.0% | 8 |
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 | 15 |
| 2 | Rigid brake pipes | 15 |
| 3 | Stop lamp | 12 |
| 4 | Shock absorbers | 10 |
| 5 | Attachment | 10 |
| 6 | Pre 01/07/2008 Turbo | 9 |
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 | 28.1% | 75 |
| 2 | Emissions & environmental | 26.6% | 71 |
| 3 | Tyres | 21.7% | 58 |
| 4 | Suspension | 19.9% | 53 |
| 5 | Lighting & signalling | 9.7% | 26 |
| 6 | Body, structure & corrosion | 8.2% | 22 |
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 | 36 | 16.7% |
| 90-120k | 70 | 20.0% |
| 120-150k | 104 | 17.3% |
| 150k+ | 53 | 13.2% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 73 | 17.8% |
| 2022 | 67 | 20.9% |
| 2023 | 55 | 16.4% |
| 2024 | 39 | 12.8% |
| 2025 | 33 | 12.1% |
What to check before buying a 2006 Gl 320
On a 2006 Gl 320, lighting & signalling is what the MOT record says goes wrong most — it appeared in 14.2% of tests. Check these areas before you commit.
- Lighting & signalling (14.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (7.9% 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.
- Emissions & environmental (5.6% 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 2006 Mercedes-Benz Gl 320s pass their MOT?
83.2% of the 267 2006 Mercedes-Benz Gl 320 MOT tests in this dataset passed — a 16.9% fail rate.
What is the most common MOT failure on a 2006 Mercedes-Benz Gl 320?
Lighting & signalling, recorded in 14.2% of tests, followed by brakes (7.9%).
Does the 2006 Gl 320 get worse with mileage?
Its MOT fail rate rises from 16.7% in the 60-90k band to 13.2% in the 150k+ band.
Methodology & source. Based on 267 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.