Diesel Fiat 500l: MOT pass rate

68.7% of diesel Fiat 500ls pass the MOT first time, measured across 11,925 DVSA tests on that fuel type alone. Average mileage at test was 74,465.

Diesel against the other Fiat 500l 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 500l specifically, petrol is the strongest at 73.7%, and this diesel version sits 1.6 points below the 70.3% model average.

What it means if you are buying one

The diesel Fiat 500l 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 500l had covered 74,465 miles at test, against 57,023 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 Fiat 500l page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel Fiat 500l

1. Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc, 3.4% of tests (4.55x the national rate for this defect)
2. Parking brake efficiency below minimum requirement, 4.1% of tests (3.12x the national rate for this defect)
3. A spring or spring component fractured or seriously weakened, 6.2% of tests (2.72x the national rate for this defect)
4. Brake disc or drum significantly and obviously worn, 1.9% of tests (2.4x the national rate for this defect)
5. Stop lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 2.5% of tests (1.83x the national rate for this defect)
6. a brake lining or pad worn below 1.5mm, 3.9% of tests (1.82x the national rate for this defect)
7. A suspension pin, bush or joint excessively worn, 8.5% of tests (1.7x the national rate for this defect)
8. Engine MIL illuminated indicating a malfunction, 2.1% of tests (1.67x the national rate for this defect)
9. A steering ball joint with excessive wear or free play, 2.2% of tests (1.66x the national rate for this defect)
10. A tyre cords visible or damaged, 2.2% of tests (1.32x the national rate for this defect)

From 11,982 DVSA-tracked diesel Fiat 500l tests, 2024, split out from the Fiat 500l's other fuel types. DVSA testers marked 6.64% 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 500l

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

1. A stub axle swivel pin and/or bush excessively worn, 1.3% of tests (2.07x the national rate for this defect)
2. Brake disc or drum significantly and obviously worn, 5.8% of tests (1.83x the national rate for this defect), also fails
3. Brake disc or drum excessively weakened, insecure or fractured, 19.7% of tests (1.61x the national rate for this defect)
4. A steering ball joint with excessive wear or free play, 1.9% of tests (1.43x the national rate for this defect), also fails
5. A tyre seriously damaged, 18.3% of tests (1.18x the national rate for this defect)
6. Tyre tread depth not in accordance with the requirements, 29.6% of tests
7. A suspension pin, bush or joint excessively worn, 11.9% of tests, also fails
8. a brake lining or pad worn below 1.5mm, 10.4% of tests, also fails
9. Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users, 5.5% of tests
10. A suspension component excessively damaged or corroded, 3.7% of tests

From 11,982 DVSA-tracked diesel Fiat 500l tests, 2024.

Other Fiat 500l fuel types

• Petrol Fiat 500l - 73.7%

All Fiat 500l MOT data · Every model