Vulching on the ATAG server.

[IvanK]

"The map is actually 1:1 scale. The reason 109s can loiter longer in the sim is that they don't have to burn half their fuel zig-zagging over some bombers that are forming up deep in France at 200 km/h: we don't have Goering threatening us with execution when we fly ( ) and since not many people fly bombers yet, there is nothing for 109 pilots to escort."

Related to this are Fuel Flows in game. Some really quick and dirty testing gives the following versus documented real world numbers:

Spitfire IIA
Climb +4/2800RPM 72gal hr. Book figures 94Gall hr
Cruise +2/2600RPM 60gal hr. Book figures 78 gall hr

BF109E4
Climb 1.35/2350 RPM (AUTO) 480Ltr/hr (106Gall/hr)
Max Cruise 1.35/2400RPM 360 ltr per hr. ... Spit value equiv is about 356Ltr hr so this value looks pretty good.

Yet to track down documented values but for a rough guide line they would similar to Spit values I would think. If some one can fill in the 109E values please do.

Blenheim IV
I4000ft at +3Lbs Boost Full Coarse pitch. 30 Gall/hr per engine i.e 60Gall hr total
Documented values 57Gall hr per Engine Total 114 Gall/hr

Edit: Added BF109E4 Climb Fuel Flow.
Notes: All Gall value are imperial.