mpg on 2500hd,1500hd, and.... ram quad cab

[farmtruc]

if you're looking to pull, the Dmax is the best choice.
the hd's will get low mileage as well.

[Show&Go]

What is the normal mpg of a d-max loaded and unloaded. Keep in mind the biggest thing I will probably be towing will be A full sized truck (mine) Everything else I see towing will probably be much smaller.
As far as comfort in-cab goes which one wins? This is also going to be the vacation ride/ out of town trip. I know none of them are going to just blow my mind with how great the mpg is. Mid 15 to 20 on the highway unloaded is what im hoping for. As with 12 to 15 loaded with a truck. Are these realistic goals?
Sierra thanks for the input. I will shy away from the Ram unless they "make me an offer I cant refuse"