You like it until you get a hole in it....

For the 190a8, as well as the p-51s, you burn the aux first, then back to auto.
For almost all planes in the game auto will work just fine. It's the special little instances where you get a very minor benefit from, say, burning left wing over right wing.
As for the comment about the P-40E, don't burn main first. The "Main" is actually very well centered low in the wing. There is another tank behind the cockpit that is more destabilizing. It's a large one too. I forget what it's called, maybe FUSE in the AH fuel selection list.
See:
http://www.zenoswarbirdvideos.com/Images/P-40/P-40FuelSys.pdfBurn it first. However, please note the last time I recall looking the AH auto fuel drain selection on the P-40E already did this. No need to manually select it.