Diesel Audi A6: MOT pass rate

82.1% of diesel Audi A6s pass the MOT first time, measured across 109,526 DVSA tests on that fuel type alone. Average mileage at test was 113,605.

Diesel against the other Audi A6 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 A6 specifically, petrol is the strongest at 84.8%, and this diesel version sits 0.2 points below the 82.3% 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 Audi A6 had covered 113,605 miles at test, against 82,566 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 A6 page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel Audi A6

1. Engine MIL illuminated indicating a malfunction, 1.8% of tests (1.38x the national rate for this defect)
2. Tyre tread depth not in accordance with the requirements, 4.2% of tests (1.32x the national rate for this defect)
3. A tyre cords visible or damaged, 2.1% of tests (1.26x the national rate for this defect)
4. A suspension pin, bush or joint excessively worn, 5.1% of tests
5. A tyre seriously damaged, 3% of tests
6. A spring or spring component fractured or seriously weakened, 1.9% of tests
7. The aim of a headlamp is not within limits laid down in the requirements, 1.6% of tests
8. A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc, 1.6% of tests
9. a brake lining or pad worn below 1.5mm, 1.3% of tests
10. A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 1% of tests

From 110,000 DVSA-tracked diesel Audi A6 tests, 2024, split out from the Audi A6's other fuel types. DVSA testers marked 5.97% 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 A6

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, 1.3% of tests (2.3x the national rate for this defect)
2. A suspension pin, bush or joint excessively worn, 23.3% of tests (1.75x the national rate for this defect), also fails
3. Tyre tread depth not in accordance with the requirements, 33.2% of tests (1.25x the national rate for this defect), also fails
4. Number plate inscription missing or illegible, 3.3% of tests (1.23x the national rate for this defect)
5. Excessive fluctuation in brake effort through each wheel revolution., 1% of tests (1.19x the national rate for this defect)
6. a brake lining or pad worn below 1.5mm, 9.7% of tests, also fails
7. Brake disc or drum excessively weakened, insecure or fractured, 9.2% of tests
8. A tyre seriously damaged, 8.9% of tests, also fails
9. A suspension component excessively damaged or corroded, 3.8% of tests
10. Brake disc or drum significantly and obviously worn, 3.5% of tests

From 110,000 DVSA-tracked diesel Audi A6 tests, 2024.

Other Audi A6 fuel types

• Petrol Audi A6 - 84.8%

All Audi A6 MOT data · Every model