Skip to content

Audi A3 vs Audi S4 tdi mhev quattro auto: reliability comparison

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

Audi A3
78%
MOT pass rate · 586,036 vehicles
Audi S4 tdi mhev quattro auto
89%
MOT pass rate · 158 vehicles
More reliable
Verdict: On MOT pass rate, the Audi S4 tdi mhev quattro auto is the more reliable of the two — 89% pass first time versus 78%. It's one signal among several; check the full breakdown below.

Head to head

Measure Audi A3 Audi S4 tdi mhev quattro auto
MOT pass rate 78% 89% ✓
MOT failure rate 22% 11% ✓
Faults & advisories per test 1.8 0.9 ✓
Dangerous-fault share 3% ✓ 8%
Average mileage 112,882 mi 38,802 mi
Sample size (vehicles) 586,036 158

Most common faults

Audi A3

  1. Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  2. Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  3. Nearside Front Tyre worn close to the legal limit (4.1.E.1)
  4. Offside Front Tyre worn close to the legal limit (4.1.E.1)
  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 S4 tdi mhev quattro auto

  1. Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  2. Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  3. Windscreen damaged but not adversely affecting driver's view (3.2 (a) (i))
  4. Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  5. Nearside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  6. Front Brake pad(s) wearing thin (1.1.13 (a) (ii))

Reliability FAQ

On MOT pass rate, the Audi S4 tdi mhev quattro auto is the more reliable of the two — 89% pass first time versus 78%. It's one signal among several; check the full breakdown below.

Full Audi A3 report Full Audi S4 tdi mhev quattro auto 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.