I bought a motorhome for the comfort and convenience while travelling. That means running the gen and ducted AC if needed. I never really understood the school of thought for curtains and what not to avoid running the gen which may impact about 1/2 MPG. Frankly I don't even monitor MPG. It's smiles to the gallon for us. If you are concerned about using fuel and partition off most of the coach to use dash air (which actually uses more fuel) then why not get a TT. I mean what's the point of a MH and all it's travelling conveniences if you aren't going to actually use them? But to each his own.