Diesel Mercedes-Benz Cla: MOT pass rate
80.4% of diesel Mercedes-Benz Clas pass the MOT first time, measured across 23,165 DVSA tests on that fuel type alone. Average mileage at test was 77,920.
Diesel against the other Mercedes-Benz Cla versions
| Fuel | Pass rate | Tests |
|---|---|---|
| Petrol | 85.2% | 34,177 |
| Diesel | 80.4% | 23,165 |
| All Mercedes-Benz Cla | 83.3% | 57,347 |
Why the fuel type changes the number
Diesels carry DPFs, EGR valves and stricter smoke limits, so emissions and exhaust faults account for failures petrol cars never see.
On the Mercedes-Benz Cla specifically, petrol is the strongest at 85.2%, and this diesel version sits 2.9 points below the 83.3% model average.
What it means if you are buying one
The diesel Mercedes-Benz Cla fails more often than the model average, so budget for the items that catch this fuel type and treat a fresh MOT as worth paying for. Check the exact car, decode the VIN and check the mileage before you bid.
Mileage is part of the answer
The average diesel Mercedes-Benz Cla had covered 77,920 miles at test, against 47,475 for the petrol. That is a shade above the middle of the range, still ordinary wear rather than a red flag, but worth checking against the service book for the car's age.
Fuel type and mileage are tangled together: diesels are usually bought by higher-mileage drivers, so some of any gap between fuels is the miles rather than the engine. The per-year figures on the Mercedes-Benz Cla page separate age from fuel if you want to isolate one.
Other Mercedes-Benz Cla fuel types
- Petrol Mercedes-Benz Cla - 85.2%