Quadcopter on Mars! Vacuum Chamber Test 2

According to my previous test, even at full throttle, an unmodified quadcopter can't fly on Mars unless the rotor efficiency is improved. Not what I hoped, yet this is consistent with the numbers I crunched from my last test. The rotors are at best 15% efficient at 7 millibars (typical for Mars) -- and in my test chamber they were also working against Earth gravity instead of Mars gravity (3/8 as much as here in Earth). To work at Mars the rotors would need to be ~30% efficient at 7 millibars -- and maybe a bit more to gain any altitude in my test chamber. As we see in Test 1, this seems entirely possible.