Diesel Audi A4: MOT pass rate

75% of diesel Audi A4s pass the MOT first time, measured across 165,081 DVSA tests on that fuel type alone. Average mileage at test was 121,863.

Diesel against the other Audi A4 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 Audi A4 specifically, petrol is the strongest at 80.6%, and this diesel version sits 1.8 points below the 76.8% model average.

What it means if you are buying one

The diesel Audi A4 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 Audi A4 had covered 121,863 miles at test, against 80,740 for the petrol. That is high mileage, so timing belts, clutches, suspension bushes and corrosion are the items worth budgeting for rather than the MOT itself.

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 Audi A4 page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel Audi A4

1. A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc, 4.2% of tests (2.72x the national rate for this defect)
2. A spring or spring component fractured or seriously weakened, 4.6% of tests (2.02x the national rate for this defect)
3. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 1.7% of tests (1.78x the national rate for this defect)
4. Engine MIL illuminated indicating a malfunction, 2.1% of tests (1.68x the national rate for this defect)
5. The aim of a headlamp is not within limits laid down in the requirements, 3.7% of tests (1.57x the national rate for this defect)
6. Tyre tread depth not in accordance with the requirements, 5% of tests (1.56x the national rate for this defect)
7. A tyre cords visible or damaged, 2.3% of tests (1.35x the national rate for this defect)
8. A suspension pin, bush or joint excessively worn, 6.7% of tests (1.34x the national rate for this defect)
9. A tyre seriously damaged, 3.2% of tests (1.16x the national rate for this defect)
10. a brake lining or pad worn below 1.5mm, 2.1% of tests

From 165,929 DVSA-tracked diesel Audi A4 tests, 2024, split out from the Audi A4's other fuel types. DVSA testers marked 5.43% 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 Audi A4

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

1. A flexible brake hose excessively damaged, deteriorated, chafed, twisted or stretched, 2.1% of tests (3.81x the national rate for this defect)
2. A suspension pin, bush or joint excessively worn, 31.9% of tests (2.39x the national rate for this defect), also fails
3. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 8.1% of tests (2.08x the national rate for this defect), also fails
4. Tyre tread depth not in accordance with the requirements, 35.5% of tests (1.33x the national rate for this defect), also fails
5. Number plate inscription missing or illegible, 3.5% of tests (1.33x the national rate for this defect)
6. A suspension component excessively damaged or corroded, 6.1% of tests (1.19x the national rate for this defect)
7. Brake disc or drum excessively weakened, insecure or fractured, 12.3% of tests
8. A tyre seriously damaged, 10.4% of tests, also fails
9. a brake lining or pad worn below 1.5mm, 10.3% of tests, also fails
10. A spring or spring component fractured or seriously weakened, 4.8% of tests, also fails

From 165,929 DVSA-tracked diesel Audi A4 tests, 2024.

Other Audi A4 fuel types

• Petrol Audi A4 - 80.6%

All Audi A4 MOT data · Every model