Diesel Kia Optima: MOT pass rate

81.6% of diesel Kia Optimas pass the MOT first time, measured across 10,322 DVSA tests on that fuel type alone. Average mileage at test was 77,762.

Diesel against the other Kia Optima 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 Optima specifically, hybrid is the strongest at 89.4%, and this diesel version sits 0.6 points below the 82.2% model average.

What it means if you are buying one

There is little to choose between fuel types on this model, so decide on running costs and mileage rather than MOT record. 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 Optima had covered 77,762 miles at test, against 82,264 for the hybrid. 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 Kia Optima page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel Kia Optima

1. a brake lining or pad worn below 1.5mm, 4.5% of tests (2.11x the national rate for this defect)
2. Significant brake effort recorded with no brake applied indicating a binding brake, 1.5% of tests (1.41x the national rate for this defect)
3. A tyre cords visible or damaged, 2.1% of tests (1.25x the national rate for this defect)
4. Tyre tread depth not in accordance with the requirements, 3.8% of tests (1.21x the national rate for this defect)
5. A tyre seriously damaged, 2.8% of tests
6. A suspension pin, bush or joint excessively worn, 1.9% of tests
7. Wiper blade missing or obviously not clearing the windscreen, 1.4% of tests
8. A steering ball joint with excessive wear or free play, 1.4% of tests
9. A suspension joint dust cover missing or no longer prevents the ingress of dirt etc, 1.1% of tests
10. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 1.1% of tests

From 10,372 DVSA-tracked diesel Kia Optima tests, 2024, split out from the Kia Optima's other fuel types. DVSA testers marked 8.67% 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 Optima

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

1. Parking brake control missing, defective or inoperative, 0.9% of tests (15.03x the national rate for this defect)
2. Excessive fluctuation in brake effort through each wheel revolution., 1.6% of tests (1.87x the national rate for this defect)
3. a brake lining or pad worn below 1.5mm, 16.8% of tests (1.8x the national rate for this defect), also fails
4. Significant brake effort recorded with no brake applied indicating a binding brake, 3.4% of tests (1.68x the national rate for this defect), also fails
5. Brake disc or drum significantly and obviously worn, 4.1% of tests (1.29x the national rate for this defect)
6. Tyre tread depth not in accordance with the requirements, 33.6% of tests (1.26x the national rate for this defect), also fails
7. Brake disc or drum excessively weakened, insecure or fractured, 13.1% of tests
8. A tyre seriously damaged, 12.5% of tests, also fails
9. A suspension pin, bush or joint excessively worn, 4.8% of tests, also fails
10. Brake pipe damaged or excessively corroded, 4.4% of tests

From 10,372 DVSA-tracked diesel Kia Optima tests, 2024.

Other Kia Optima fuel types

• Hybrid Kia Optima - 89.4%

All Kia Optima MOT data · Every model