Bentley Derby 3.5 vs Bentley Unknown: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Bentley Derby 3.5
97%
MOT pass rate · 3 vehicles
Bentley Unknown
90%
MOT pass rate · 9,548 vehicles
Verdict: On MOT pass rate the Bentley Derby 3.5 (97%) and Bentley Unknown (90%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Head to head
| Measure | Bentley Derby 3.5 | Bentley Unknown |
|---|---|---|
| MOT pass rate | 97% ✓ | 90% |
| MOT failure rate | 3% ✓ | 10% |
| Faults & advisories per test | 0.0 ✓ | 0.9 |
| Dangerous-fault share | 0% ✓ | 7% |
| Average mileage | 42,056 mi | 34,409 mi |
| Sample size (vehicles) | 3 | 9,548 |
Most common faults
Bentley Derby 3.5
- Offside Rear position lamp(s) not working (1.1.A.3b)
- Offside Stop lamp not working (1.2.1b)
- Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
Bentley Unknown
- COVID-19 6 MONTH EXTENSION
- Parking brake efficiency less than 50% of the required value (1.4.2 (a) (ii))
- Parking brake: efficiency below requirements (3.7.B.7)
- Windscreen washer provides insufficient washer liquid (8.2.3)
- Oil leak
- Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
Reliability FAQ
On MOT pass rate the Bentley Derby 3.5 (97%) and Bentley Unknown (90%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.
Full Bentley Derby 3.5 report Full Bentley Unknown 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.