2005 Mercedes-Benz Cl 500 — MOT failures & pass rate
The 2005 Mercedes-Benz Cl 500 passed 83.1% of its 924 recorded MOT tests. Against all cars of a similar age (27.6% fail rate), the 2005 Cl 500 comes out 10.7pp better. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (7.8%) and suspension (6.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are ball joint, rigid brake pipes and headlamp aim — ball joint alone was recorded 32 times.
A 150k+ example is materially riskier than a 0-30k one: 22.6% versus 0.0%.
Brakes is the most common advisory, noted on 29.9% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 18.7% in 2021 to 14.5% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 7.8% | 72 |
| 2 | Suspension | 6.1% | 56 |
| 3 | Brakes | 4.5% | 42 |
| 4 | Tyres | 3.8% | 35 |
| 5 | Visibility | 2.4% | 22 |
| 6 | Steering | 1.5% | 14 |
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 | 32 |
| 2 | Rigid brake pipes | 29 |
| 3 | Headlamp aim | 27 |
| 4 | Shock absorbers | 27 |
| 5 | Side repeaters | 20 |
| 6 | Tread depth | 20 |
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 | 29.9% | 276 |
| 2 | Suspension | 26.1% | 241 |
| 3 | Tyres | 25.2% | 233 |
| 4 | Lighting & signalling | 10.2% | 94 |
| 5 | Emissions & environmental | 9.2% | 85 |
| 6 | Visibility | 7.1% | 66 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 35 | 0.0% |
| 30-60k | 101 | 5.9% |
| 60-90k | 272 | 18.4% |
| 90-120k | 304 | 17.1% |
| 120-150k | 157 | 22.9% |
| 150k+ | 53 | 22.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 230 | 18.7% |
| 2022 | 196 | 16.3% |
| 2023 | 186 | 16.7% |
| 2024 | 160 | 17.5% |
| 2025 | 152 | 14.5% |
What to check before buying a 2005 Cl 500
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 7.8% of tests. Start there.
- Lighting & signalling (7.8% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (6.1% 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.
- Brakes (4.5% 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.
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 2005 Mercedes-Benz Cl 500s pass their MOT?
83.1% of the 924 2005 Mercedes-Benz Cl 500 MOT tests in this dataset passed — a 16.9% fail rate.
What is the most common MOT failure on a 2005 Mercedes-Benz Cl 500?
Lighting & signalling, recorded in 7.8% of tests, followed by suspension (6.1%).
Does the 2005 Cl 500 get worse with mileage?
Its MOT fail rate rises from 0.0% in the 0-30k band to 22.6% in the 150k+ band.
Methodology & source. Based on 924 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.