Diesel Mazda 3: MOT pass rate
71% of diesel Mazda 3s pass the MOT first time, measured across 15,010 DVSA tests on that fuel type alone. Average mileage at test was 94,502.
Diesel against the other Mazda 3 versions
| Fuel | Pass rate | Tests |
|---|---|---|
| Petrol | 74.3% | 93,122 |
| Diesel | 71% | 15,010 |
| All Mazda 3 | 73.9% | 108,163 |
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 Mazda 3 specifically, petrol is the strongest at 74.3%, and this diesel version sits 2.9 points below the 73.9% model average.
What it means if you are buying one
The diesel Mazda 3 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 Mazda 3 had covered 94,502 miles at test, against 73,153 for the petrol. That is above average, the point where suspension bushes, drop links and exhaust corrosion start showing up as advisories before they become failures.
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 Mazda 3 page separate age from fuel if you want to isolate one.
Other Mazda 3 fuel types
- Petrol Mazda 3 - 74.3%