Mercedes-Benz Clk vs Porsche 911
The Porsche 911 has the better MOT record of the two — 9.7% fail rate versus 25.3% for the Mercedes-Benz Clk across comparable years. The biggest single difference is suspension, where the Clk records failures noticeably more often.
25.3%
Clk fail rate
9.7%
911 fail rate
15.69pp
Difference
Side by side
| Metric | Mercedes-Benz Clk | Porsche 911 |
|---|---|---|
| MOT tests analysed | 204,964 | 252,686 |
| Pass rate | 74.7% | 90.3% |
| Fail rate | 25.3% | 9.7% |
Where they differ
| Category | Clk | 911 |
|---|---|---|
| Suspension | 14.7% | 1.6% |
| Lighting & signalling | 11.2% | 4.8% |
| Brakes | 8.2% | 2.0% |
| Visibility | 4.2% | 0.0% |
| Tyres | 6.1% | 2.3% |
| Emissions & environmental | 0.0% | 1.9% |
Methodology & source. 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.