Audi A4 ultra s line tdi vs Audi A6: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Audi A4 ultra s line tdi
91%
MOT pass rate · 114 vehicles
More reliable
Audi A6
78%
MOT pass rate · 246,602 vehicles
Verdict: On MOT pass rate, the Audi A4 ultra s line tdi is the more reliable of the two — 91% pass first time versus 78%. It's one signal among several; check the full breakdown below.
Head to head
| Measure | Audi A4 ultra s line tdi | Audi A6 |
|---|---|---|
| MOT pass rate | 91% ✓ | 78% |
| MOT failure rate | 9% ✓ | 22% |
| Faults & advisories per test | 0.0 ✓ | 1.7 |
| Dangerous-fault share | — ✓ | 2% |
| Average mileage | 94,203 mi | 136,441 mi |
| Sample size (vehicles) | 114 | 246,602 |
Most common faults
Audi A4 ultra s line tdi
No fault breakdown available.
Audi A6
- Nearside Front Tyre worn close to the legal limit (4.1.E.1)
- Offside Front Tyre worn close to the legal limit (4.1.E.1)
- Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
- Offside Rear Tyre worn close to the legal limit (4.1.E.1)
Reliability FAQ
On MOT pass rate, the Audi A4 ultra s line tdi is the more reliable of the two — 91% pass first time versus 78%. It's one signal among several; check the full breakdown below.
Full Audi A4 ultra s line tdi report Full Audi A6 report Most reliable cars
Pass rates are computed over completed (pass/fail) MOT tests. Reliability also depends on age, mileage and upkeep — see each model's page for the full picture.