Diesel Ford Fiesta: MOT pass rate

63.6% of diesel Ford Fiestas pass the MOT first time, measured across 179,820 DVSA tests on that fuel type alone. Average mileage at test was 105,233.

Diesel against the other Ford Fiesta 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 Ford Fiesta specifically, petrol is the strongest at 73.5%, and this diesel version sits 8.6 points below the 72.2% model average.

What it means if you are buying one

The diesel Ford Fiesta 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 Ford Fiesta had covered 105,233 miles at test, against 67,593 for the petrol. That is above average and into the range where cambelts and water pumps are due if they have not already been done, so ask for the service history rather than take the mileage on trust.

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 Ford Fiesta page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel Ford Fiesta

1. A stub axle swivel pin and/or bush excessively worn, 3% of tests (20.51x the national rate for this defect)
2. Smoke opacity levels exceed the manufacturer's specified limit, 3.4% of tests (12.76x the national rate for this defect)
3. A steering ball joint with excessive wear or free play, 5.4% of tests (4.13x the national rate for this defect)
4. Stop lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 5% of tests (3.64x the national rate for this defect)
5. A suspension pin, bush or joint excessively worn, 13.7% of tests (2.73x the national rate for this defect)
6. The strength or continuity of the load bearing structure within 30cm of any sub-frame, spring or suspension component mounting (a 'prescribed area') is significantly reduced or inadequately repaired, 2.6% of tests (2.71x the national rate for this defect)
7. Exhaust system leaking or insecure, 2.3% of tests (2.27x 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, 2.5% of tests (2.02x the national rate for this defect)
9. A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 4.1% of tests (1.84x the national rate for this defect)
10. A tyre cords visible or damaged, 3.1% of tests (1.84x the national rate for this defect)

From 180,784 DVSA-tracked diesel Ford Fiesta tests, 2024, split out from the Ford Fiesta's other fuel types. DVSA testers marked 5.26% 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 Ford Fiesta

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, 8.5% of tests (13.21x the national rate for this defect), also fails
2. A wheel badly distorted or wear between wheel and hub at spigot mounting, 7.8% of tests (7.32x the national rate for this defect)
3. A steering ball joint with excessive wear or free play, 4.5% of tests (3.41x the national rate for this defect), also fails
4. A spring or spring component fractured or seriously weakened, 15.2% of tests (3.21x the national rate for this defect)
5. Lamp emitted colour, position or intensity not in accordance with the requirements, 3.8% of tests (2.75x the national rate for this defect)
6. Number plate inscription missing or illegible, 4.9% of tests (1.84x the national rate for this defect)
7. Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users, 8.2% of tests (1.48x the national rate for this defect)
8. Brake pipe damaged or excessively corroded, 8.3% of tests (1.34x the national rate for this defect)
9. Tyre tread depth not in accordance with the requirements, 33.1% of tests (1.24x the national rate for this defect)
10. A suspension pin, bush or joint excessively worn, 16.3% of tests (1.22x the national rate for this defect), also fails

From 180,784 DVSA-tracked diesel Ford Fiesta tests, 2024.

Other Ford Fiesta fuel types

• Petrol Ford Fiesta - 73.5%

All Ford Fiesta MOT data · Every model