Driving 120 miles in Florida with out the generator, air,or dash air running takes about 2 hours of actual driving time, takes about 12 gallons and costs about $47.00. Driving with the air and generator on will use about 14 gallons and cost about $54.00, but this is without dash air. In real life, I drive with dash air and run the generator and central air as needed intermittently. I have the coach as comfortable as I want(actually my wife wants, and use a minimum of extra diesel. Actually, my wife wants to make sure that the three Labs are comfortable.
Paul