Wrong. The new V6 has adaptive knock spark control. If you put in higher octane gas, the ECU will advance timing and the car will make more power. I can't wait till mne comes in and I can try 100 octan race gas at the track.
I agree with this. Most new cars now have spark knock sensors which will allow the ECU to optimize timing for the fuel that you're running. I've tried this in different cars and have noticed a difference, some seems like more than others.
I don't have any idea what the actual increase to power might be, but it would be interesting if somebody had one of those dynamic performance measuring tools to check the difference.