Hi,
I towed all last season with a SWB trooper 3.1 and have now traded it for a LWB Bighorn. I have just aquired the BH and have only managed a brief sojorn with the van - suffice to say that it towed superbly but no indication of MPG as it was only a mile or so.
I found that the SWB (manual) averaged 30 mpg solo and 25 towing. I would expect a little less with the BH as it is auto and weighs more. However in the couple of tankfulls I have used so far it seems to be keeping up to 30 mpg so maybe I will be suprised. First outing will be next week and a 300 mile round trip, so ask me then.
Regarding the 3.1 Troop generally I would say they are hard to beat for reliability and towing ability - I should know too as I have towed with most of the credible opposition i.e. Jeeps, Shoguns and Landrovers. The LWB pitches up and down markedly less than the LWB which was very apparent from my short tow so I would endorse Lutz's similar comments. He has had his for five years by the way so that tells you something!
Final note on economy, it does of course depend on what you are towing. My figures are for towing a Bailey Oklamhoma at around 1500kg, when towing a two horse trailer the consumpton plumets below 20 mpg
Good choice of motor and have fun.