Actually the IFR still do take it out of their own fuel and replace it with fuel converted from goods right?
I know a change was made because they used to give away all their own fuel and then crash, but IIRC the change was just that they wouldn't give away all their own fuel (probably only to half). If not most of the IFR are useless since they have no cargo capacity, and honestly they are mostly useless (the Viking being the sole exception I can think of, has possible use since it can refuel off carriers and then refuel non-carrier capable aircraft, but it's too much micromanagement headache even for me).
A lot of them have horrible fuel efficiency as well. I imagine when originally designed their fuel cargo load was added to most of them as fuel instead of cargo since that was the way it was done, and it took a lot of playtesting to see that it was a serious design flaw, and most of them never got rebalanced.
Granted since IFR wasn't a thing during WW2 I guess they won't get fixed for 1936 either, but it's probably something that should go to unit errata somewhere someday.
Anyway, yes, I was thinking the same thing as Balth said, stop spamming the same question all over the board, it makes it harder to help you, it makes his job harder since he does the forum moderation too, and his time could be put to better use than cleaning up after us, it also makes it harder for other people who might make use of the information or join in the discussion to as well. And yes, I'm being somewhat hypocritical since I'm responding in 2 threads myself. I reprimand myself as well.
While we're on it, try to keep to 1 subject per topic (again I am as guilty as anyone of digressing all over the place...but it doesn't mean we shouldn't try). Again because it makes it harder for the info to be found. It also makes it less likely that it will be seen or given serious consideration by BG. It makes Balth happy, and if you keep Balth happy he will go above and beyond to try to find answers to your questions.
A lot of info you are looking for is in the older 2020 threads, although most anything conclusive made it to the wiki. Balth and others (I think Ruges really did the bulk of it...and of course most of the usual suspects around here contributed) put together a huge amount of info there. Yes, there's a ton of stuff nobody seems to have good answers to, but sometimes you need to do your own research and testing.