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Audi A 4 tdi vs Audi A6: reliability comparison

MOT pass rates, common faults and mileage compared from real UK MOT data.

Audi A 4 tdi
58%
MOT pass rate · 2 vehicles
Audi A6
78%
MOT pass rate · 246,602 vehicles
Verdict: On MOT pass rate the Audi A 4 tdi (58%) and Audi A6 (78%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Head to head

Measure Audi A 4 tdi Audi A6
MOT pass rate 58% 78% ✓
MOT failure rate 42% 22% ✓
Faults & advisories per test 0.8 ✓ 1.7
Dangerous-fault share 0% ✓ 2%
Average mileage 209,592 mi 136,441 mi
Sample size (vehicles) 2 246,602

Most common faults

Audi A 4 tdi

  1. Nearside Front Track rod end ball joint has excessive play (2.2.B.1f)
  2. Offside Front Lower Suspension arm has excessive play in a ball joint (2.4.G.2)
  3. both front suspension lower front arms have some lift.
  4. brake discs are corroded & lipped
  5. Nearside Rear Brake pad(s) wearing thin (3.5.1g)
  6. Offside Rear Brake pad(s) wearing thin (3.5.1g)

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)

Reliability FAQ

On MOT pass rate the Audi A 4 tdi (58%) and Audi A6 (78%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Full Audi A 4 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.