You should get better performance in the S position as long as the fuel is good enough to prevent knocking or pre ignition.
I'm not sure if these cars have a knock sensor. I dont think they do, so the car doesnt "know" what fuel its using.
If the 92 octane is causing knocking perhaps this would reduce your power / increase consumption.

Over here in the UK the fuel is 95 or 97octane and mine seems fine on the 95 with the resistor in any position.