Diesel Kia Rio: MOT pass rate

66.1% of diesel Kia Rios pass the MOT first time, measured across 19,769 DVSA tests on that fuel type alone. Average mileage at test was 89,386.

Diesel against the other Kia Rio 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 Kia Rio specifically, petrol is the strongest at 76.8%, and this diesel version sits 8.6 points below the 74.7% model average.

What it means if you are buying one

The diesel Kia Rio 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 Kia Rio had covered 89,386 miles at test, against 59,898 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 Kia Rio page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel Kia Rio

1. A steering ball joint with excessive wear or free play, 5.5% of tests (4.2x the national rate for this defect)
2. A suspension joint dust cover missing or no longer prevents the ingress of dirt etc, 4.8% of tests (2.63x the national rate for this defect)
3. Significant brake effort recorded with no brake applied indicating a binding brake, 2.4% of tests (2.29x the national rate for this defect)
4. Parking brake efficiency below minimum requirement, 2.7% of tests (2.11x the national rate for this defect)
5. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 3.5% of tests (2.06x the national rate for this defect)
6. Brake pipe damaged or excessively corroded, 2.1% of tests (1.94x the national rate for this defect)
7. A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 3.9% of tests (1.76x the national rate for this defect)
8. A suspension pin, bush or joint excessively worn, 8.7% of tests (1.73x the national rate for this defect)
9. Engine MIL illuminated indicating a malfunction, 2.2% of tests (1.7x the national rate for this defect)
10. Wiper blade missing or obviously not clearing the windscreen, 3% of tests (1.6x the national rate for this defect)

From 19,873 DVSA-tracked diesel Kia Rio tests, 2024, split out from the Kia Rio's other fuel types. DVSA testers marked 5.67% 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 Kia Rio

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

1. A steering ball joint with excessive wear or free play, 4.3% of tests (3.22x the national rate for this defect), also fails
2. Significant brake effort recorded with no brake applied indicating a binding brake, 5.2% of tests (2.62x the national rate for this defect), also fails
3. A suspension component excessively damaged or corroded, 11.3% of tests (2.19x the national rate for this defect)
4. Brake pipe damaged or excessively corroded, 10.5% of tests (1.69x the national rate for this defect), also fails
5. 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, 2.3% of tests (1.53x the national rate for this defect)
6. Brake disc or drum excessively weakened, insecure or fractured, 18.4% of tests (1.5x the national rate for this defect)
7. Number plate inscription missing or illegible, 3.9% of tests (1.48x the national rate for this defect)
8. Lamp emitted colour, position or intensity not in accordance with the requirements, 1.9% of tests (1.38x the national rate for this defect)
9. A suspension pin, bush or joint excessively worn, 17.3% of tests (1.29x the national rate for this defect), also fails
10. Tyre tread depth not in accordance with the requirements, 32.9% of tests (1.23x the national rate for this defect)

From 19,873 DVSA-tracked diesel Kia Rio tests, 2024.

Other Kia Rio fuel types

• Petrol Kia Rio - 76.8%

All Kia Rio MOT data · Every model