I have also heard that if you run to much octane it will slow the car down.
I will tell you what. The next time I race my car (Spring) I will test this theory.
I suppose to run the car on pump gas on motor, and 116 on spray. I will just make a pass on motor with 116 and see what happens. Sorry about the Spring thing but its a lttle cold out here with this white stuff on the ground.
Later