Skip to content

Audi A6 vs Audi A8 s line blk ed 50 tdi quat a: 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 A8 s line blk ed 50 tdi quat a
92%
MOT pass rate · 227 vehicles
More reliable
Verdict: On MOT pass rate, the Audi A8 s line blk ed 50 tdi quat a is the more reliable of the two — 92% pass first time versus 78%. It's one signal among several; check the full breakdown below.

Head to head

Measure Audi A6 Audi A8 s line blk ed 50 tdi quat a
MOT pass rate 78% 92% ✓
MOT failure rate 22% 8% ✓
Faults & advisories per test 1.7 0.7 ✓
Dangerous-fault share 2% ✓ 8%
Average mileage 136,441 mi 59,635 mi
Sample size (vehicles) 246,602 227

Most common faults

Audi A6

  1. Nearside Front Tyre worn close to the legal limit (4.1.E.1)
  2. Offside Front Tyre worn close to the legal limit (4.1.E.1)
  3. Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  4. Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  5. Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
  6. Offside Rear Tyre worn close to the legal limit (4.1.E.1)

Audi A8 s line blk ed 50 tdi quat a

  1. Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  2. Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  3. Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  4. Front Brake disc worn, pitted or scored, but not seriously weakened (1.1.14 (a) (ii))
  5. Front Brake pad(s) wearing thin (1.1.13 (a) (ii))
  6. Rear Brake pad(s) wearing thin (1.1.13 (a) (ii))

Reliability FAQ

On MOT pass rate, the Audi A8 s line blk ed 50 tdi quat a is the more reliable of the two — 92% pass first time versus 78%. It's one signal among several; check the full breakdown below.

Full Audi A6 report Full Audi A8 s line blk ed 50 tdi quat a 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.