2009 Mercedes-Benz R-Class — MOT failures & pass rate
Across 1,286 MOT tests, the 2009 Mercedes-Benz R-Class recorded a 77.9% pass rate. MPVs of a similar age fail 26.9% of the time, so this is 4.8pp better than the group it competes with. Failures cluster in lighting & signalling, brakes and emissions & environmental.
What the MOT record shows
No single area dominates — lighting & signalling (12.0%) and brakes (10.8%) 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 rbt (sp) — position lamp alone was recorded 75 times.
Condition tracks the odometer closely. Failures run at 18.6% in the 30-60k band and 23.2% in the 150k+ band, a 4.6-point spread.
Brakes is the most common advisory, noted on 33.8% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 23.9% in 2021 to 22.0% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 12.0% | 155 |
| 2 | Brakes | 10.8% | 139 |
| 3 | Emissions & environmental | 6.6% | 85 |
| 4 | Tyres | 4.0% | 51 |
| 5 | Suspension | 3.7% | 48 |
| 6 | Body, structure & corrosion | 3.5% | 45 |
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 | 75 |
| 2 | Rigid brake pipes | 47 |
| 3 | Rbt (sp) | 41 |
| 4 | On or after 01/07/2008 | 40 |
| 5 | Joints | 39 |
| 6 | Flexible brake hoses | 36 |
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 | 33.8% | 435 |
| 2 | Emissions & environmental | 26.9% | 346 |
| 3 | Tyres | 22.9% | 294 |
| 4 | Suspension | 16.8% | 216 |
| 5 | Body, structure & corrosion | 13.3% | 171 |
| 6 | Lighting & signalling | 9.1% | 117 |
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 | 18.6% |
| 60-90k | 200 | 18.0% |
| 90-120k | 426 | 22.8% |
| 120-150k | 359 | 22.8% |
| 150k+ | 237 | 23.2% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 1,233 | 22.1% |
| Petrol | 53 | 22.6% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 339 | 23.9% |
| 2022 | 296 | 22.0% |
| 2023 | 266 | 18.1% |
| 2024 | 226 | 24.3% |
| 2025 | 159 | 22.0% |
What to check before buying a 2009 R-Class
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 12.0% of tests. Start there.
- Lighting & signalling (12.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (10.8% 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.
- Emissions & environmental (6.6% 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 2009 Mercedes-Benz R-Classs pass their MOT?
77.9% of the 1,286 2009 Mercedes-Benz R-Class MOT tests in this dataset passed — a 22.1% fail rate.
What is the most common MOT failure on a 2009 Mercedes-Benz R-Class?
Lighting & signalling, recorded in 12.0% of tests, followed by brakes (10.8%).
Does the 2009 R-Class get worse with mileage?
Its MOT fail rate rises from 18.6% in the 30-60k band to 23.2% in the 150k+ band.
Methodology & source. Based on 1,286 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.