[jime57]

Just completed 1,314 miles on 120.023 gallons. That works out to be 10.95 mpg, so 11 mpg can be done by just using the techniques I outlined earlier. It was mostly Interstate, and that makes a difference of course.

I have 30,000 lb. Newmar with a small car/dolly in tow.

I'd think that some good aero work would get us to 12 mpg.

I'm seeing the long haul truckers using side plates on their trailers between the truck rear wheels and the trailer wheels. Apparently they are finding that closing off that huge open area improves the aero of the combination. Of course, that is pretty much taken care of on most motorhomes by the inclusion of compartment doors in that area. A short boattail still looks like most productive first step.