Ranges from 14.9 to 15.25 with the mac long tune. 15% fuel same on 2 tacs. My friend said I was crazy to fly that D***N thing, but he flys scale birds. Lots of engines will turn the RPM when moded, it is just a question of how long. The problem is I want to do 3D with this bird but the RPM have to be up on the long pipe. I am thinking of going with some type of 4c. I guess the long tune was handy from my pylon days. Works, but the expo is set way low and still at that it is tricky.