2011 Mercedes-Benz Cl 500 — MOT failures & pass rate
The 2011 Mercedes-Benz Cl 500 passed 84.2% of its 366 recorded MOT tests. Against all cars of a similar age (23.0% fail rate), the 2011 Cl 500 comes out 7.2pp better. Failures cluster in suspension, emissions & environmental and tyres.
What the MOT record shows
No single area dominates — suspension (4.4%) and emissions & environmental (3.8%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are catalyst emissions, ball joint and malfunction indicator lamp — catalyst emissions alone was recorded 14 times.
Mileage matters less than usual here: the 2011 Cl 500 fails 13.6% of the time in the 30-60k band and 13.3% at 120-150k, a spread of only 0.3 points.
Advisories point at the next bill rather than this one: tyres was flagged on 18.0% of tests without failing them.
The trend is worsening — 13.1% of tests failed in 2021 against 15.2% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 4.4% | 16 |
| 2 | Emissions & environmental | 3.8% | 14 |
| 3 | Tyres | 3.5% | 13 |
| 4 | Brakes | 2.5% | 9 |
| 5 | Lighting & signalling | 1.9% | 7 |
| 6 | Road wheels | 1.1% | 4 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Catalyst emissions | 14 |
| 2 | Ball joint | 12 |
| 3 | Malfunction indicator lamp | 9 |
| 4 | Tread depth | 7 |
| 5 | Registration plates | 4 |
| 6 | Brake discs | 4 |
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 | 18.0% | 66 |
| 2 | Brakes | 16.4% | 60 |
| 3 | Suspension | 15.3% | 56 |
| 4 | Road wheels | 2.2% | 8 |
| 5 | Visibility | 1.9% | 7 |
| 6 | Other defects | 1.4% | 5 |
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 | 88 | 13.6% |
| 60-90k | 127 | 18.1% |
| 90-120k | 89 | 19.1% |
| 120-150k | 30 | 13.3% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 84 | 13.1% |
| 2022 | 76 | 17.1% |
| 2023 | 79 | 19.0% |
| 2024 | 61 | 14.8% |
| 2025 | 66 | 15.2% |
What to check before buying a 2011 Cl 500
On a 2011 Cl 500, suspension is what the MOT record says goes wrong most — it appeared in 4.4% of tests. Check these areas before you commit.
- Suspension (4.4% 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.
- Emissions & environmental (3.8% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Tyres (3.5% 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 2011 Mercedes-Benz Cl 500s pass their MOT?
84.2% of the 366 2011 Mercedes-Benz Cl 500 MOT tests in this dataset passed — a 15.8% fail rate.
What is the most common MOT failure on a 2011 Mercedes-Benz Cl 500?
Suspension, recorded in 4.4% of tests, followed by emissions & environmental (3.8%).
Does the 2011 Cl 500 get worse with mileage?
Its MOT fail rate rises from 13.6% in the 30-60k band to 13.3% in the 120-150k band.
Methodology & source. Based on 366 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.