Bmw 520 vs Bmw R 18 roctane: 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 R 18 roctane
100%
MOT pass rate · 72 vehicles
Verdict: On MOT pass rate the Bmw 520 (78%) and Bmw R 18 roctane (100%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Head to head
| Measure | Bmw 520 | Bmw R 18 roctane |
|---|---|---|
| MOT pass rate | 78% | 100% ✓ |
| MOT failure rate | 22% | 0% ✓ |
| Faults & advisories per test | 1.6 | 0.0 ✓ |
| Dangerous-fault share | 3% | — ✓ |
| Average mileage | 134,460 mi | 1,600 mi |
| Sample size (vehicles) | 156,398 | 72 |
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 R 18 roctane
No fault breakdown available.
Reliability FAQ
On MOT pass rate the Bmw 520 (78%) and Bmw R 18 roctane (100%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Full Bmw 520 report Full Bmw R 18 roctane 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.