Diesel Mercedes-Benz 300: MOT pass rate
76.1% of diesel Mercedes-Benz 300s pass the MOT first time, measured across 522 DVSA tests on that fuel type alone. Average mileage at test was 147,671.
Diesel against the other Mercedes-Benz 300 versions
| Fuel | Pass rate | Tests |
|---|---|---|
| Petrol | 81.9% | 2,254 |
| Diesel | 76.1% | 522 |
| All Mercedes-Benz 300 | 80.9% | 2,789 |
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 300 specifically, petrol is the strongest at 81.9%, and this diesel version sits 4.8 points below the 80.9% model average.
What it means if you are buying one
The diesel Mercedes-Benz 300 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 300 had covered 147,671 miles at test, against 107,424 for the petrol. That is very high mileage. Clutches, dual-mass flywheels and head gaskets have usually been through at least one repair by this point, so ask for evidence rather than assume the car is original everywhere.
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 300 page separate age from fuel if you want to isolate one.
Other Mercedes-Benz 300 fuel types
- Petrol Mercedes-Benz 300 - 81.9%