I have a friend who has lamented over the fuel flow system of previous MS flight sims, and I have not verified for myself if this is still the case, but I would expect that not much has changed in the fact that fuel flow is calculated with net thrust, which is not accurate at all, and leads to significantly reduced fuel consumption at altitude compared to real life, and thus requiring unrealistic drag added to the aircraft at high altitudes to have accurate fuel burn. He has mentioned that a fix as simple as calculating fuel burn with Gross Thrust instead of Net Thrust should be enough of a fix in it of itself. If this has already been fixed and is the case however, please let me know so I can have the thread locked.
Thats interesting and certainly matches up with my testing for the Hunter. We could get pretty accurate fuel flow at a given altitude, but if we went lower, the burn decreased and higher it increased which is (broadly speaking) the opposite of what should be happening. (This was with a jet) using the TURBINEENGINEDATA config and correctly populating JET_density_on_FF_table
When tuning the fuelflow with altitude, the parameter indeed is JET_density_on_FF_table.
However, MSFS uses poundforce instead of poundmass. Difference is a factor of 31…
Also the table MUST be sorted hi-altitude to low-altitude, and MUST start from approx 60.000 ft.
And then ONLY the Fuel Flow value will behave accordingly, NOT the CorFF.
With this I finally got it to work.
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Thanks for the protip, this will definitely help. I know other devs have tweaked drag at altitude to try and get fuel burn to be correct in previous sims, but this negatively affects the flight model and makes the drift down performance far worse than real life. I am not sure if this is more common of a workaround for devs or not.
It has been, yes. Developers can now use the use_gross_thrust_on_fuelflow param in engine.cfg, which if memory serves was added around November or December last year.