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Audi 100 vs Audi A4: reliability comparison

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

Audi 100
65%
MOT pass rate · 14,565 vehicles
Audi A4
76%
MOT pass rate · 568,515 vehicles
More reliable
Verdict: On MOT pass rate, the Audi A4 is the more reliable of the two — 76% pass first time versus 65%. It's one signal among several; check the full breakdown below.

Head to head

Measure Audi 100 Audi A4
MOT pass rate 65% 76% ✓
MOT failure rate 35% 24% ✓
Faults & advisories per test 2.4 1.9 ✓
Dangerous-fault share 0% ✓ 2%
Average mileage 150,787 mi 133,841 mi
Sample size (vehicles) 14,565 568,515

Most common faults

Audi 100

  1. Parking brake: efficiency below requirements (3.7.B.7)
  2. Fuel pipe/s corroded
  3. Nearside Front Tyre worn close to the legal limit (4.1.E.1)
  4. Nearside Rear wheel bearing has slight play (2.6.2)
  5. Offside Front Tyre worn close to the legal limit (4.1.E.1)
  6. Oil leak

Audi A4

  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 Rear Tyre worn close to the legal limit (4.1.E.1)
  4. Offside Rear Tyre worn close to the legal limit (4.1.E.1)
  5. Under-trays fitted obscuring some underside components
  6. Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))

Reliability FAQ

On MOT pass rate, the Audi A4 is the more reliable of the two — 76% pass first time versus 65%. It's one signal among several; check the full breakdown below.

Full Audi 100 report Full Audi A4 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.