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Mazda 121 vs Mazda 6: reliability comparison

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

Mazda 121
63%
MOT pass rate · 6,017 vehicles
Mazda 6
75%
MOT pass rate · 159,403 vehicles
More reliable
Verdict: On MOT pass rate, the Mazda 6 is the more reliable of the two — 75% pass first time versus 63%. It's one signal among several; check the full breakdown below.

Head to head

Measure Mazda 121 Mazda 6
MOT pass rate 63% 75% ✓
MOT failure rate 37% 25% ✓
Faults & advisories per test 2.8 1.9 ✓
Dangerous-fault share 0% ✓ 2%
Average mileage 81,994 mi 113,866 mi
Sample size (vehicles) 6,017 159,403

Most common faults

Mazda 121

  1. Service brake: efficiency below requirements (3.7.B.7)
  2. Parking brake: efficiency below requirements (3.7.B.7)
  3. Nearside Rear Brake pipe slightly corroded (3.6.B.2c)
  4. Nearside Front Tyre worn close to the legal limit (4.1.E.1)
  5. Offside Rear Brake pipe slightly corroded (3.6.B.2c)
  6. Offside Front Tyre worn close to the legal limit (4.1.E.1)

Mazda 6

  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. Rear Brake pad(s) wearing thin (3.5.1g)
  5. Offside Rear Tyre worn close to the legal limit (4.1.E.1)
  6. Under-trays fitted obscuring some underside components

Reliability FAQ

On MOT pass rate, the Mazda 6 is the more reliable of the two — 75% pass first time versus 63%. It's one signal among several; check the full breakdown below.

Full Mazda 121 report Full Mazda 6 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.