Bmw 3 series vs Bmw M635: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Bmw 3 series
75%
MOT pass rate · 996,044 vehicles
Bmw M635
83%
MOT pass rate · 8 vehicles
Verdict: On MOT pass rate the Bmw 3 series (75%) and Bmw M635 (83%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Head to head
| Measure | Bmw 3 series | Bmw M635 |
|---|---|---|
| MOT pass rate | 75% | 83% ✓ |
| MOT failure rate | 25% | 17% ✓ |
| Faults & advisories per test | 2.0 ✓ | 2.1 |
| Dangerous-fault share | 2% | 0% ✓ |
| Average mileage | 128,558 mi | 113,319 mi |
| Sample size (vehicles) | 996,044 | 8 |
Most common faults
Bmw 3 series
- Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
- Offside Rear Tyre worn close to the legal limit (4.1.E.1)
- Nearside Front Tyre worn close to the legal limit (4.1.E.1)
- Offside Front Tyre worn close to the legal limit (4.1.E.1)
- Under-trays fitted obscuring some underside components
- Oil leak, but not excessive (8.4.1 (a) (i))
Bmw M635
- Front Brake disc worn, pitted or scored, but not seriously weakened (1.1.14 (a) (ii))
- Rear Brake disc worn, pitted or scored, but not seriously weakened (1.1.14 (a) (ii))
- Nearside Front Brake pipe corroded, covered in grease or other material (1.1.11 (c))
- Offside Front Headlamp not working on dipped beam (4.1.1 (a) (ii))
- Both seats play
- Child Seat fitted not allowing full inspection of adult belt
Reliability FAQ
On MOT pass rate the Bmw 3 series (75%) and Bmw M635 (83%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Full Bmw 3 series report Full Bmw M635 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.