2009 Mercedes-Benz Cl — MOT failures & pass rate
Across 296 MOT tests, the 2009 Mercedes-Benz Cl recorded an 80.4% pass rate. That is effectively the same as coupes & convertibles of a similar age (20.2% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in brakes, suspension and tyres.
What the MOT record shows
No single area dominates — brakes (8.8%) and suspension (8.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are ball joint, rbt (sp) and parking brake performance — ball joint alone was recorded 21 times.
Mileage matters less than usual here: the 2009 Cl fails 15.4% of the time in the 30-60k band and 17.1% at 120-150k, a spread of only 1.8 points.
Brakes is the most common advisory, noted on 24.3% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 25.0% in 2021 to 20.4% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Brakes | 8.8% | 26 |
| 2 | Suspension | 8.5% | 25 |
| 3 | Tyres | 5.7% | 17 |
| 4 | Lighting & signalling | 4.7% | 14 |
| 5 | Visibility | 2.0% | 6 |
| 6 | Emissions & environmental | 1.7% | 5 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Ball joint | 21 |
| 2 | Rbt (sp) | 12 |
| 3 | Parking brake performance | 8 |
| 4 | Brake discs | 7 |
| 5 | Rigid brake pipes | 5 |
| 6 | Position lamp | 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 | 24.3% | 72 |
| 2 | Suspension | 19.9% | 59 |
| 3 | Tyres | 14.2% | 42 |
| 4 | Emissions & environmental | 5.7% | 17 |
| 5 | Road wheels | 4.4% | 13 |
| 6 | Visibility | 4.4% | 13 |
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 | 52 | 15.4% |
| 60-90k | 138 | 21.7% |
| 90-120k | 53 | 22.6% |
| 120-150k | 35 | 17.1% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 68 | 25.0% |
| 2022 | 59 | 10.2% |
| 2023 | 60 | 18.3% |
| 2024 | 60 | 23.3% |
| 2025 | 49 | 20.4% |
What to check before buying a 2009 Cl
The failure pattern for this year is specific enough to inspect against: brakes accounted for 8.8% of tests. Start there.
- Brakes (8.8% 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.
- Suspension (8.5% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Tyres (5.7% 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.
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 Cls pass their MOT?
80.4% of the 296 2009 Mercedes-Benz Cl MOT tests in this dataset passed — a 19.6% fail rate.
What is the most common MOT failure on a 2009 Mercedes-Benz Cl?
Brakes, recorded in 8.8% of tests, followed by suspension (8.5%).
Does the 2009 Cl get worse with mileage?
Its MOT fail rate rises from 15.4% in the 30-60k band to 17.1% in the 120-150k band.
Methodology & source. Based on 296 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.