Diesel Fiat 500: MOT pass rate

61.9% of diesel Fiat 500s pass the MOT first time, measured across 3,906 DVSA tests on that fuel type alone. Average mileage at test was 88,815.

Diesel against the other Fiat 500 versions

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 Fiat 500 specifically, petrol is the strongest at 72.1%, and this diesel version sits 10 points below the 71.9% model average.

What it means if you are buying one

The diesel Fiat 500 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. Buying a damaged one? run it through the analyzer, check the exact car, decode the VIN and check the mileage before you bid.

Mileage is part of the answer

The average diesel Fiat 500 had covered 88,815 miles at test, against 56,402 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 Fiat 500 page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel Fiat 500

1. A shock absorber bush excessively worn, 3.5% of tests (18.19x the national rate for this defect)
2. Parking brake inoperative on one side, 3.4% of tests (5.68x the national rate for this defect)
3. Parking brake efficiency below minimum requirement, 7.4% of tests (5.67x the national rate for this defect)
4. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 4.9% of tests (5.16x the national rate for this defect)
5. Exhaust system leaking or insecure, 3.4% of tests (3.32x the national rate for this defect)
6. A suspension pin, bush or joint excessively worn, 12% of tests (2.39x the national rate for this defect)
7. The aim of a headlamp is not within limits laid down in the requirements, 5.5% of tests (2.35x the national rate for this defect)
8. A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED, 2.8% of tests (2.31x the national rate for this defect)
9. A tyre cords visible or damaged, 3.4% of tests (2x the national rate for this defect)
10. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 3.3% of tests (1.98x the national rate for this defect)

From 3,956 DVSA-tracked diesel Fiat 500 tests, 2024, split out from the Fiat 500's other fuel types. DVSA testers marked 4.78% of these flagged defects as "dangerous", against 5.11% nationally. See which fuel type fails on the most dangerous defects nationally for how that compares across the whole fleet.

Most common MOT advisories on a diesel Fiat 500

Flagged but doesn't fail the car, a different list from the failures above.

1. A shock absorber bush excessively worn, 4.7% of tests (9.81x the national rate for this defect), also fails
2. A spring or spring component fractured or seriously weakened, 26.9% of tests (5.69x the national rate for this defect)
3. Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users, 19.7% of tests (3.54x the national rate for this defect)
4. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 10.9% of tests (2.79x the national rate for this defect), also fails
5. A wheel badly distorted or wear between wheel and hub at spigot mounting, 2.9% of tests (2.68x the national rate for this defect)
6. Exhaust system leaking or insecure, 7% of tests (2.44x the national rate for this defect), also fails
7. A brake hose ferrule excessively corroded, 3% of tests (2.36x the national rate for this defect)
8. A suspension component excessively damaged or corroded, 11.5% of tests (2.23x the national rate for this defect)
9. A suspension pin, bush or joint excessively worn, 19.6% of tests (1.47x the national rate for this defect), also fails
10. A tyre seriously damaged, 17.9% of tests (1.16x the national rate for this defect)

From 3,956 DVSA-tracked diesel Fiat 500 tests, 2024.

Other Fiat 500 fuel types

• Petrol Fiat 500 - 72.1%

All Fiat 500 MOT data · Every model