It depends on what planes you fly. I've noticed that the Macchi C.205 uses the aux tank first if you let it on auto. But, if you go to manual, you can use the small wing tanks first, and it seems to handle better like that. Something I always do is to take 50 or 75% fuel, and drop tank(s). Then, you can burn up the drop tanks first, and if you get bounced, you can drop them, and have a light plane with only 50 or 75% fuel. Hope that makes sense.
Another thing to remember is there is a fuel multiplier in the MA. You are actually using fuel much faster than a plane would in real life.
[This message has been edited by LJK Raubvogel (edited 02-07-2001).]