Bmw 3 series vs Bmw 635: 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 635
79%
MOT pass rate · 3,974 vehicles
More reliable
Verdict: On MOT pass rate, the Bmw 635 is the more reliable of the two — 79% pass first time versus 75%. It's one signal among several; check the full breakdown below.
Head to head
| Measure | Bmw 3 series | Bmw 635 |
|---|---|---|
| MOT pass rate | 75% | 79% ✓ |
| MOT failure rate | 25% | 21% ✓ |
| Faults & advisories per test | 2.0 | 1.7 ✓ |
| Dangerous-fault share | 2% | 2% |
| Average mileage | 128,558 mi | 130,476 mi |
| Sample size (vehicles) | 996,044 | 3,974 |
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 635
- Under-trays fitted obscuring some underside components
- Offside Rear Tyre worn close to the legal limit (4.1.E.1)
- Oil leak, but not excessive (8.4.1 (a) (i))
- Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
- Engine covers fitted obscuring some components in the engine bay
- Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
Reliability FAQ
On MOT pass rate, the Bmw 635 is the more reliable of the two — 79% pass first time versus 75%. It's one signal among several; check the full breakdown below.
Full Bmw 3 series report Full Bmw 635 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.