Quadman8 is correct about the power potential of high octane fuel.  The octane rating is not a rating on the fuels power potential .  It is a rating on the fuels resistance to detonation. 

I have not found oxygenated race gas to increase the power more than about 1.5% when the jetting is optimized.  I have seen alot of holed and siezed pistons when oxygenated fuel was used and the jets were not right.