Bentley S3 vs Bentley Unknown: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Bentley S3
86%
MOT pass rate · 195 vehicles
Bentley Unknown
90%
MOT pass rate · 9,548 vehicles
More reliable
Verdict: On MOT pass rate, the Bentley Unknown is the more reliable of the two — 90% pass first time versus 86%. It's one signal among several; check the full breakdown below.
Head to head
| Measure | Bentley S3 | Bentley Unknown |
|---|---|---|
| MOT pass rate | 86% | 90% ✓ |
| MOT failure rate | 14% | 10% ✓ |
| Faults & advisories per test | 0.9 | 0.9 |
| Dangerous-fault share | 1% ✓ | 7% |
| Average mileage | 58,719 mi | 34,409 mi |
| Sample size (vehicles) | 195 | 9,548 |
Most common faults
Bentley S3
- Oil leak
- Service brake: efficiency below requirements (3.7.B.7)
- Offside Rear Shock absorber has a light misting of oil (2.7.3)
- Nearside Rear Shock absorber has a light misting of oil (2.7.3)
- Windscreen washer provides insufficient washer liquid (8.2.3)
- Offside Rear Brake pipe slightly corroded (3.6.B.2c)
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 Unknown is the more reliable of the two — 90% pass first time versus 86%. It's one signal among several; check the full breakdown below.
Full Bentley S3 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.