It's fun to say the least. I made a 230 mile trip through on I-79 through WV and tried some technics found on this site. I averaged around 65 mph the entire trip, and made 2 stops. On large hills I would give the car just enough gas to make it up it at 55 (70 mph speed limit) and going down I would put it in neutral and the car would usually get up to 80 before I'd slow it down with the brakes.
33 MPG average over 230 miles. 25 mpg EPA. I'm confident I can break 35 mpg at this point, so I might try for 40. No mods done to the car either, the CEL came out for the 0420 code (catalytic converter crap) so I dont know if thats effecting mileage or not.
Still not bad for a wagon filled to the brim with tools and cargo, an auto trans, perm awd, 2 tons, and a foot off the ground.
I plan to start doing a few aero mods whenever I get back home, starting with either some nice 3/8ths skid plates or fender skirts. I'm not sure how good the MPG will be while I'm here, as I have to drag some oaks around the farm. Yeah, we don't own a truck.