2008 Mercedes-Benz Cl 500 — MOT failures & pass rate
Across 779 MOT tests, the 2008 Mercedes-Benz Cl 500 recorded an 83.3% pass rate. All cars of a similar age fail 26.3% of the time, so this is 9.6pp better than the group it competes with. Failures cluster in brakes, suspension and tyres.
What the MOT record shows
Brakes dominates the failure mix at 8.7% of all tests — 3.5 points clear of suspension, so it is the first thing to check.
At component level the recurring items are rigid brake pipes, rbt (sp) and tread depth — rigid brake pipes alone was recorded 40 times.
Mileage matters less than usual here: the 2008 Cl 500 fails 15.0% of the time in the 30-60k band and 18.6% at 120-150k, a spread of only 3.6 points.
Advisories point at the next bill rather than this one: brakes was flagged on 27.9% of tests without failing them.
The trend is improving — the fail rate fell from 18.7% in 2021 to 14.7% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Brakes | 8.7% | 68 |
| 2 | Suspension | 5.3% | 41 |
| 3 | Tyres | 4.8% | 37 |
| 4 | Lighting & signalling | 2.6% | 20 |
| 5 | Visibility | 2.3% | 18 |
| 6 | Emissions & environmental | 1.5% | 12 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rigid brake pipes | 40 |
| 2 | Rbt (sp) | 32 |
| 3 | Tread depth | 19 |
| 4 | Shock absorbers | 19 |
| 5 | Ball joint | 19 |
| 6 | Electronic parking brake | 16 |
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 | 27.9% | 217 |
| 2 | Tyres | 20.2% | 157 |
| 3 | Suspension | 18.5% | 144 |
| 4 | Emissions & environmental | 6.3% | 49 |
| 5 | Visibility | 3.1% | 24 |
| 6 | Other defects | 2.9% | 23 |
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 | 147 | 15.0% |
| 60-90k | 266 | 15.4% |
| 90-120k | 275 | 18.6% |
| 120-150k | 70 | 18.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 166 | 18.7% |
| 2022 | 154 | 14.9% |
| 2023 | 158 | 17.7% |
| 2024 | 151 | 17.2% |
| 2025 | 150 | 14.7% |
What to check before buying a 2008 Cl 500
On a 2008 Cl 500, brakes is what the MOT record says goes wrong most — it appeared in 8.7% of tests. Check these areas before you commit.
- Brakes (8.7% 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 (5.3% 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 (4.8% 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 2008 Mercedes-Benz Cl 500s pass their MOT?
83.3% of the 779 2008 Mercedes-Benz Cl 500 MOT tests in this dataset passed — a 16.7% fail rate.
What is the most common MOT failure on a 2008 Mercedes-Benz Cl 500?
Brakes, recorded in 8.7% of tests, followed by suspension (5.3%).
Does the 2008 Cl 500 get worse with mileage?
Its MOT fail rate rises from 15.0% in the 30-60k band to 18.6% in the 120-150k band.
Methodology & source. Based on 779 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.