Originally Posted by imag

As the video shows, some amount of high octane is not a waste in this car - the timing adjusts and you get some of the benefit. I definitely notice the difference when I put in a few gallons at the track (of course, our maximum normally available octane here is 91).

I'm not saying to fill the tank with 107, but mixing in some 107 can have noticeable affect. My guess is the max usable octane is about 96 or so, at which point you stop getting any benefit with the stock motor.