In MSFS and various other flight sims games I had before, I noticed that fuel consumption at high altitudes is lower even at full throttle. In FG (as far as I know) the fuel consumption stays the same unless you throttle down.
Which is correct? All this time I've been led to the belief by those games that at high altitudes the fuel consumption of the plane will be much lower on the same throttle setting as it would be at a lower altitude.
I did some basic research into this and found this :
Because the air is less dense at higher altitudes, drag reduces, but for the same reason thrust reduces. The balance of these two effects in any particular case determines the altitude at which the maximum envelope airspeed will be reached. - Source
So can anyone explain, in not-too-technical-terms, how it actually is? Is it that when thrust reduces the engine will have a lower thrust automatically and therefore - lower fuel consumption even when the throttle is pushed to 100% (for example)?
I find that with FlightGear I can "cruise" at high altitudes (or any altitudes) with the throttle at about 30% with no problems. The only effect that high altitudes seem to have is that the Mach speed is higher than indicated airspeed.