Diesel SEAT Leon: MOT pass rate

76.9% of diesel SEAT Leons pass the MOT first time, measured across 74,694 DVSA tests on that fuel type alone. Average mileage at test was 104,336.

Diesel against the other SEAT Leon 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 SEAT Leon specifically, petrol is the strongest at 82.4%, and this diesel version sits 3 points below the 79.9% model average.

What it means if you are buying one

The diesel SEAT Leon 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 SEAT Leon had covered 104,336 miles at test, against 64,810 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 SEAT Leon page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel SEAT Leon

1. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 3.3% of tests (3.45x the national rate for this defect)
2. Significant brake effort recorded with no brake applied indicating a binding brake, 2% of tests (1.95x the national rate for this defect)
3. A spring or spring component fractured or seriously weakened, 3.9% of tests (1.69x the national rate for this defect)
4. A suspension joint dust cover missing or no longer prevents the ingress of dirt etc, 2.8% of tests (1.54x the national rate for this defect)
5. a brake lining or pad worn below 1.5mm, 3% of tests (1.4x the national rate for this defect)
6. Tyre tread depth not in accordance with the requirements, 4.4% of tests (1.37x the national rate for this defect)
7. A tyre cords visible or damaged, 2.3% of tests (1.36x the national rate for this defect)
8. Engine MIL illuminated indicating a malfunction, 1.7% of tests (1.36x the national rate for this defect)
9. The aim of a headlamp is not within limits laid down in the requirements, 3% of tests (1.26x the national rate for this defect)
10. Parking brake efficiency below minimum requirement, 1.6% of tests (1.22x the national rate for this defect)

From 75,005 DVSA-tracked diesel SEAT Leon tests, 2024, split out from the SEAT Leon's other fuel types. DVSA testers marked 5.65% 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 SEAT Leon

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

1. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 23.6% of tests (6.03x the national rate for this defect), also fails
2. Significant brake effort recorded with no brake applied indicating a binding brake, 5% of tests (2.5x the national rate for this defect), also fails
3. A suspension component excessively damaged or corroded, 8.5% of tests (1.64x the national rate for this defect)
4. A spring or spring component fractured or seriously weakened, 6.9% of tests (1.45x the national rate for this defect), also fails
5. Number plate inscription missing or illegible, 3.8% of tests (1.43x the national rate for this defect)
6. Brake disc or drum excessively weakened, insecure or fractured, 16.1% of tests (1.31x the national rate for this defect)
7. Tyre tread depth not in accordance with the requirements, 33.5% of tests (1.26x the national rate for this defect), also fails
8. a brake lining or pad worn below 1.5mm, 11.6% of tests (1.24x the national rate for this defect), also fails
9. A tyre seriously damaged, 13% of tests
10. A suspension pin, bush or joint excessively worn, 10.4% of tests

From 75,005 DVSA-tracked diesel SEAT Leon tests, 2024.

Other SEAT Leon fuel types

• Petrol SEAT Leon - 82.4%

All SEAT Leon MOT data · Every model