@Skua Further tests showed that all tanks are drained at the same rate percentage wise (large mixed with small fuselage tanks)... tried fuselage vs wing to but for some reason 15 gal of fuel weighs more in a 5 long square wing then in a 5 long square fuselage??? I balanced them without fuel, then added fuel... and the wing hit the ground... hmm that's annoying... 8 versions later and still the same, so I abandoned the ide... Thanks for the comments always nice to get feedback : )

@Pauciloquent huh, right you are. Nice job for a well-designed test. I guess it must just be a tiny amount then, but it will be for the same reason

@Skua In one of the tests I found that it does in fact lose weight but way to little...

You got it, planes don't lose weight at all as the use fuel. I think this is primarily because we can't decide which parts of the plane to use fuel from first, so it would ruin the CoM-CoL relationship on a lot of planes