Porsche 911 vs Porsche Cayman r s-a: reliability comparison
MOT pass rates, common faults and mileage compared from real UK MOT data.
Porsche 911
85%
MOT pass rate · 74,656 vehicles
Porsche Cayman r s-a
95%
MOT pass rate · 45 vehicles
More reliable
Verdict: On MOT pass rate, the Porsche Cayman r s-a is the more reliable of the two — 95% pass first time versus 85%. It's one signal among several; check the full breakdown below.
Head to head
| Measure | Porsche 911 | Porsche Cayman r s-a |
|---|---|---|
| MOT pass rate | 85% | 95% ✓ |
| MOT failure rate | 15% | 5% ✓ |
| Faults & advisories per test | 1.1 | 0.5 ✓ |
| Dangerous-fault share | 1% ✓ | 2% |
| Average mileage | 70,982 mi | 35,766 mi |
| Sample size (vehicles) | 74,656 | 45 |
Most common faults
Porsche 911
- 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)
- Under-trays fitted obscuring some underside components
- Nearside Front Tyre worn close to the legal limit (4.1.E.1)
- Offside Front Tyre worn close to the legal limit (4.1.E.1)
- Oil leak, but not excessive (8.4.1 (a) (i))
Porsche Cayman r s-a
- 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))
- Nearside Front Suspension arm ball joint has slight play (5.3.4 (a) (i))
- Rear Brake disc worn, pitted or scored, but not seriously weakened (1.1.14 (a) (ii))
- Offside Front Suspension arm ball joint has slight play (5.3.4 (a) (i))
- Rear tyres worn on inner edges
Reliability FAQ
On MOT pass rate, the Porsche Cayman r s-a is the more reliable of the two — 95% pass first time versus 85%. It's one signal among several; check the full breakdown below.
Full Porsche 911 report Full Porsche Cayman r s-a 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.