Well, I have a TB42 carbied GQ with a 350 Holley on it (don't ask)
Running 32's, 2" lift, roof racks and drawers, pulling about 2.7t;
on road (85-95kmh) I get about 19.6L/100km on ULP and 20.5 on LPG.
Fully loaded towing a 17.5 ft caravan (75-95) I get about 24 on ULP and 28 on LPG.

Just acquired a TD42T GU wagon, stealing the donk.
Will post figures when she's in!

Wonder if I can bolt the TB42 into the GU and sell it on. hmmmmmm. :-)