Bmw 120 vs Bmw 520: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Bmw 120
80%
MOT pass rate · 62,290 vehicles
More reliable
Bmw 520
78%
MOT pass rate · 156,398 vehicles
Verdict: On MOT pass rate, the Bmw 120 is the more reliable of the two — 80% pass first time versus 78%. It's one signal among several; check the full breakdown below.
Head to head
| Measure | Bmw 120 | Bmw 520 |
|---|---|---|
| MOT pass rate | 80% ✓ | 78% |
| MOT failure rate | 20% ✓ | 22% |
| Faults & advisories per test | 1.7 | 1.6 ✓ |
| Dangerous-fault share | 3% | 3% |
| Average mileage | 115,908 mi | 134,460 mi |
| Sample size (vehicles) | 62,290 | 156,398 |
Most common faults
Bmw 120
- 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 Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
- Under-trays fitted obscuring some underside components
- Nearside Front Brake hose slightly deteriorated (1.1.12 (b) (ii))
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))
Reliability FAQ
On MOT pass rate, the Bmw 120 is the more reliable of the two — 80% pass first time versus 78%. It's one signal among several; check the full breakdown below.
Full Bmw 120 report Full Bmw 520 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.