opened up my manual and found this:
himax 2015 4100kV:
no load current = 0.80A
efficient operating current = 5-12A
recommended esc = 10A

looked a bit more and saw this:

himax 2015 3600kV:
no load current = 0.54A
efficient operating current = 3-8A
recommended esc = 8A

2.6A is a high no load current. don't know a whole lot about brushless terminology, but i guess higher no load current means more current is required to spin same RPM without a load. so i think lower no load current = higher efficiency, but not sure if things change a lot when the motor is loaded.[]

hope this helps.