FUEL MILEAGE
probably 9 to 10 mpg dependng on driving speed, total weight, engine size and rear axle ratio. You will need a load levelong hitch and a friction sway bar (maybe 2). Not famliar with a mechancal sway control wth spring bar. The load leveling hitch has spring bars but these are for equalzing the hitch weight on rear of tow vehicle. Is the van 1/2 or 3/4 ton chassic?