I just bought a TM 3023 from a dealer in Texas I drove my 2003 Suburan out to get it got 18.9 MPG on the way out at 75-80 mph.
Had the dealer install an Equal-I-Zer WD hitch
with 1000 lb. bars no sway control as this type hitch incorporates it in the design.
Drove eight hundred miles back a 60-65 mph (suburban has 5.3 liter engine) got 15.7 mpg which is roughly 85%, I think your van would do a good job but I agree make sure it has an oil cooler the bigger the better if thats possible.
