2012 Mercedes-Benz R-Class — MOT failures & pass rate
1,672 MOT tests on the 2012 Mercedes-Benz R-Class are in this dataset, and 83.2% of them passed. Against MPVs of a similar age (22.6% fail rate), the 2012 R-Class comes out 5.8pp better. Failures cluster in brakes, lighting & signalling and body, structure & corrosion.
What the MOT record shows
No single area dominates — brakes (5.9%) and lighting & signalling (5.9%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are joints, position lamp and headlamp aim — joints alone was recorded 87 times.
Condition tracks the odometer closely. Failures run at 10.4% in the 30-60k band and 20.1% in the 150k+ band, a 9.7-point spread.
Tyres is the most common advisory, noted on 23.2% of tests — work that passed today but is likely due soon.
The trend is worsening — 16.3% of tests failed in 2021 against 21.7% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Brakes | 5.9% | 98 |
| 2 | Lighting & signalling | 5.9% | 98 |
| 3 | Body, structure & corrosion | 5.2% | 87 |
| 4 | Tyres | 3.9% | 65 |
| 5 | Emissions & environmental | 2.6% | 44 |
| 6 | Suspension | 2.3% | 39 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Joints | 87 |
| 2 | Position lamp | 52 |
| 3 | Headlamp aim | 38 |
| 4 | Rbt (sp) | 38 |
| 5 | Rigid brake pipes | 36 |
| 6 | Malfunction indicator lamp | 33 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 23.2% | 387 |
| 2 | Brakes | 21.2% | 354 |
| 3 | Body, structure & corrosion | 14.2% | 237 |
| 4 | Emissions & environmental | 12.5% | 209 |
| 5 | Suspension | 8.5% | 142 |
| 6 | Other defects | 7.2% | 120 |
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 | 135 | 10.4% |
| 60-90k | 573 | 17.6% |
| 90-120k | 504 | 16.5% |
| 120-150k | 285 | 17.2% |
| 150k+ | 169 | 20.1% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 363 | 16.3% |
| 2022 | 344 | 14.2% |
| 2023 | 318 | 13.5% |
| 2024 | 334 | 18.6% |
| 2025 | 313 | 21.7% |
What to check before buying a 2012 R-Class
The failure pattern for this year is specific enough to inspect against: brakes accounted for 5.9% of tests. Start there.
- Brakes (5.9% 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.
- Lighting & signalling (5.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Body, structure & corrosion (5.2% of tests): The one to take seriously on older cars — corrosion to structural areas can be costly and is an MOT failure. Typical repair: £200–£1,500+.
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 R-Classs pass their MOT?
83.2% of the 1,672 2012 Mercedes-Benz R-Class MOT tests in this dataset passed — a 16.8% fail rate.
What is the most common MOT failure on a 2012 Mercedes-Benz R-Class?
Brakes, recorded in 5.9% of tests, followed by lighting & signalling (5.9%).
Does the 2012 R-Class get worse with mileage?
Its MOT fail rate rises from 10.4% in the 30-60k band to 20.1% in the 150k+ band.
Methodology & source. Based on 1,672 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.