Mazda 3 vs Mazda B: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Mazda 3
78%
MOT pass rate · 164,058 vehicles
Mazda B
68%
MOT pass rate · 4 vehicles
Verdict: On MOT pass rate the Mazda 3 (78%) and Mazda B (68%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Head to head
| Measure | Mazda 3 | Mazda B |
|---|---|---|
| MOT pass rate | 78% ✓ | 68% |
| MOT failure rate | 22% ✓ | 32% |
| Faults & advisories per test | 2.0 ✓ | 2.9 |
| Dangerous-fault share | 3% | 2% ✓ |
| Average mileage | 90,915 mi | 173,537 mi |
| Sample size (vehicles) | 164,058 | 4 |
Most common faults
Mazda 3
- Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Nearside Front Tyre worn close to the legal limit (4.1.E.1)
- Rear Sub-frame corroded but not seriously weakened (5.3.3 (b) (i))
- Offside Front Tyre worn close to the legal limit (4.1.E.1)
- Front Brake pad(s) wearing thin (1.1.13 (a) (ii))
Mazda B
- Oil leak, but not excessive (8.4.1 (a) (i))
- Offside Front Seat belt webbing slightly damaged or frayed (7.1.2 (b) (ii))
- Rear Brake pad(s) wearing thin (1.1.13 (a) (ii))
- Front Brake pad(s) wearing thin (3.5.1g)
- Nearside Front Anti-roll bar linkage ball joint has slight play (5.3.4 (a) (i))
- Offside Front Tyre slightly damaged/cracking or perishing (5.2.3 (d) (ii))
Reliability FAQ
On MOT pass rate the Mazda 3 (78%) and Mazda B (68%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Full Mazda 3 report Full Mazda B 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.