The whole drive (prop, motor, ESC, battery, plugs and cables). I like such drive layout with quite big prop pitch. It's not that efficient in climb (40%, 12.5 A current draw) but it is in cruise (47%, 3.75 A).
Overall efficiency is the light blue line in the lower diagrams. Note the small rpm change ("unloading") over flight speed (yellow line).
Last edited by UStik; 07-31-2014 at 08:38 AM.