Audi A6 vs Audi S5 v8 quattro: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Audi A6
78%
MOT pass rate · 246,602 vehicles
Audi S5 v8 quattro
85%
MOT pass rate · 69 vehicles
Verdict: On MOT pass rate the Audi A6 (78%) and Audi S5 v8 quattro (85%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Head to head
| Measure | Audi A6 | Audi S5 v8 quattro |
|---|---|---|
| MOT pass rate | 78% | 85% ✓ |
| MOT failure rate | 22% | 15% ✓ |
| Faults & advisories per test | 1.7 | 0.2 ✓ |
| Dangerous-fault share | 2% ✓ | 4% |
| Average mileage | 136,441 mi | 92,633 mi |
| Sample size (vehicles) | 246,602 | 69 |
Most common faults
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)
Audi S5 v8 quattro
- Child seat fitted not allowing full inspection of adult belt
- Offside Front Lower Suspension arm rubber bush deteriorated but not resulting in excessive movement rear arm (2.4.G.2)
- Offside Rear Nail in tyre
- Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Nearside Front Upper Suspension arm pin or bush worn but not resulting in excessive movement Inner rear side (5.3.4 (a) (i))
- Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
Reliability FAQ
On MOT pass rate the Audi A6 (78%) and Audi S5 v8 quattro (85%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Full Audi A6 report Full Audi S5 v8 quattro 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.