2008 Mercedes-Benz CLS — MOT failures & pass rate
9,389 MOT tests on the 2008 Mercedes-Benz CLS are in this dataset, and 76.8% of them passed. That is effectively the same as executive cars of a similar age (22.5% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in suspension, lighting & signalling and tyres.
What the MOT record shows
No single area dominates — suspension (10.8%) and lighting & signalling (8.0%) 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 tread depth — ball joint alone was recorded 759 times.
Condition tracks the odometer closely. Failures run at 19.2% in the 0-30k band and 23.3% in the 150k+ band, a 4.1-point spread.
The petrol cars hold up better: 19.5% fail against 23.5% for diesel, a 4.1-point gap across 9,389 tests.
Brakes is the most common advisory, noted on 34.7% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 23.7% in 2021 to 20.5% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 10.8% | 1,017 |
| 2 | Lighting & signalling | 8.0% | 753 |
| 3 | Tyres | 7.9% | 741 |
| 4 | Brakes | 7.8% | 737 |
| 5 | Visibility | 3.4% | 317 |
| 6 | Emissions & environmental | 3.2% | 301 |
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 | 759 |
| 2 | Rigid brake pipes | 572 |
| 3 | Tread depth | 405 |
| 4 | Headlamp aim | 302 |
| 5 | Coil spring | 283 |
| 6 | Track rod end | 276 |
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 | 34.7% | 3,256 |
| 2 | Tyres | 28.1% | 2,635 |
| 3 | Suspension | 26.0% | 2,441 |
| 4 | Emissions & environmental | 11.9% | 1,115 |
| 5 | Other defects | 10.2% | 960 |
| 6 | Body, structure & corrosion | 7.2% | 676 |
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 | 78 | 19.2% |
| 30-60k | 450 | 15.1% |
| 60-90k | 1,716 | 22.1% |
| 90-120k | 2,858 | 23.2% |
| 120-150k | 2,545 | 25.3% |
| 150k+ | 1,735 | 23.3% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 8,608 | 23.5% |
| Petrol | 781 | 19.5% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 2,204 | 23.7% |
| 2022 | 2,112 | 23.9% |
| 2023 | 1,926 | 23.1% |
| 2024 | 1,720 | 24.1% |
| 2025 | 1,427 | 20.5% |
What to check before buying a 2008 CLS
The failure pattern for this year is specific enough to inspect against: suspension accounted for 10.8% of tests. Start there.
- Suspension (10.8% 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.
- Lighting & signalling (8.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (7.9% 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 CLSs pass their MOT?
76.8% of the 9,389 2008 Mercedes-Benz CLS MOT tests in this dataset passed — a 23.2% fail rate.
What is the most common MOT failure on a 2008 Mercedes-Benz CLS?
Suspension, recorded in 10.8% of tests, followed by lighting & signalling (8.0%).
Does the 2008 CLS get worse with mileage?
Its MOT fail rate rises from 19.2% in the 0-30k band to 23.3% in the 150k+ band.
Methodology & source. Based on 9,389 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.