Bmw 520 vs Bmw M135i auto: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Bmw 520
78%
MOT pass rate · 156,398 vehicles
Bmw M135i auto
92%
MOT pass rate · 177 vehicles
More reliable
Verdict: On MOT pass rate, the Bmw M135i auto is the more reliable of the two — 92% pass first time versus 78%. It's one signal among several; check the full breakdown below.
Head to head
| Measure | Bmw 520 | Bmw M135i auto |
|---|---|---|
| MOT pass rate | 78% | 92% ✓ |
| MOT failure rate | 22% | 8% ✓ |
| Faults & advisories per test | 1.6 | 0.0 ✓ |
| Dangerous-fault share | 3% | — ✓ |
| Average mileage | 134,460 mi | 78,804 mi |
| Sample size (vehicles) | 156,398 | 177 |
Most common faults
Bmw 520
- 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)
- Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Nearside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Under-trays fitted obscuring some underside components
- Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
Bmw M135i auto
No fault breakdown available.
Reliability FAQ
On MOT pass rate, the Bmw M135i auto is the more reliable of the two — 92% pass first time versus 78%. It's one signal among several; check the full breakdown below.
Full Bmw 520 report Full Bmw M135i auto 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.