We drove a 25 ft, 2000 Phoenix Flyer (by Fleetwood) for 4 years, and we got 10.5 mpg towing or not. You can imagine my surprise when we replaced it with a 2004 Jamboree (also by Fleetwood) which gets about 7 mpg. The Jamboree is a foot longer and weighs about 100 pounds more, and has the same engine. I don't know about the transmission. I called Ford, Fleetwood, and anybody else I could think of, and the typical response was something like "WOW you sure did good with that Phoenix Flyer. You should have kept it" which wasn't too helpful. I think the problem is that the computer is programmed for performance, not for economy. I swear the the thing looks down the road and says to itself "OMG, there's rise in the roadway ahead, I'd better shift down". It doesn't allow the engine to work. I'm convinced that if I could find someone willing and able to do it, the program could be tweaked to fix this. But so far I've not been able to find anyone. So I just continue to sit in the right hand lane with the cruise control set at 55, like I've always done, and let the diesel pushers and semis blast by me at 65 or 70.
