2005 Mercedes-Benz CLS — MOT failures & pass rate
6,369 MOT tests on the 2005 Mercedes-Benz CLS are in this dataset, and 79.7% of them passed. Executive cars of a similar age fail 24.1% of the time, so this is 3.8pp better than the group it competes with. Failures cluster in suspension, lighting & signalling and tyres.
What the MOT record shows
No single area dominates — suspension (8.6%) and lighting & signalling (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, headlamp and headlamp aim — ball joint alone was recorded 393 times.
Mileage is the strongest signal on the record: 10.9% of 0-30k cars fail, rising to 24.7% once past 150k — 2.3× the risk.
Split by fuel, diesel examples fail 3.6pp more often than petrol ones (23.1% vs 19.5%) — worth weighing if you have a choice.
Advisories point at the next bill rather than this one: brakes was flagged on 32.2% of tests without failing them.
The trend is improving — the fail rate fell from 21.0% in 2021 to 19.1% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 8.6% | 545 |
| 2 | Lighting & signalling | 8.5% | 544 |
| 3 | Tyres | 6.6% | 418 |
| 4 | Brakes | 6.2% | 394 |
| 5 | Emissions & environmental | 4.4% | 279 |
| 6 | Visibility | 2.5% | 157 |
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 | 393 |
| 2 | Headlamp | 310 |
| 3 | Headlamp aim | 273 |
| 4 | Rigid brake pipes | 230 |
| 5 | Tread depth | 223 |
| 6 | Malfunction indicator lamp | 219 |
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 | 32.2% | 2,050 |
| 2 | Tyres | 26.0% | 1,654 |
| 3 | Suspension | 23.6% | 1,504 |
| 4 | Emissions & environmental | 13.2% | 838 |
| 5 | Lighting & signalling | 12.0% | 765 |
| 6 | Body, structure & corrosion | 9.8% | 623 |
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 | 92 | 10.9% |
| 30-60k | 586 | 15.2% |
| 60-90k | 1,554 | 18.5% |
| 90-120k | 1,970 | 21.4% |
| 120-150k | 1,325 | 21.1% |
| 150k+ | 831 | 24.7% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 4,835 | 19.5% |
| Diesel | 1,529 | 23.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,528 | 21.0% |
| 2022 | 1,441 | 20.1% |
| 2023 | 1,267 | 19.9% |
| 2024 | 1,152 | 21.3% |
| 2025 | 981 | 19.1% |
What to check before buying a 2005 CLS
On a 2005 CLS, suspension is what the MOT record says goes wrong most — it appeared in 8.6% of tests. Check these areas before you commit.
- Suspension (8.6% 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 (8.5% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (6.6% 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 2005 Mercedes-Benz CLSs pass their MOT?
79.7% of the 6,369 2005 Mercedes-Benz CLS MOT tests in this dataset passed — a 20.3% fail rate.
What is the most common MOT failure on a 2005 Mercedes-Benz CLS?
Suspension, recorded in 8.6% of tests, followed by lighting & signalling (8.5%).
Does the 2005 CLS get worse with mileage?
Its MOT fail rate rises from 10.9% in the 0-30k band to 24.7% in the 150k+ band.
Methodology & source. Based on 6,369 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.