Going to a single axle verses a dually would force us to literally Not to load much in the camper and in fact according to the charts, the single axle highest payload will not accommodate the camper I have when loaded. Our weigh ticket with two adults, 2 full tanks of gas, about 25 gallons of water, and gear ( no AC, awnings, or generator) puts us about 3600 pounds. We will be adding roof AC this spring and possibly a generator. Certainly not enough carrying capacity on new truck even with gas engine and certainly wouldn't have an option to ever upgrade to a larger camper and so dually it is. The dilemma is gas verses diesel and mpg based on your truck/engine and speed so we can decide which way we want to go. We appreciate all of your responses.