You don't need any nitro at all, we run theseengines in Pylon racers and they perform very well without it. There will be plenty of people in here who shoot me down for this but the less nitro the better as far as I am concerned. The stuff is acidic and eats away the bearings in the motor if you leave any fuel in the motor.

These engines pull a Viper / Sonic / Syd racing plane around the sky very well using a blend of methonol and degummed castor for my money the less nitro you use the better