Hey welcome to the forum.. that is one hell of a loaded Ram you got there.. Heck even us young bucks would need to do some research to get er all figured out with all the toys. For miliage.. the Rams are actually really good compared to most other trucks.. Ford talks out their ass about the eco-boost miliage and no one ever hits what is stated. Coming from a GM family and many friends with Fords and Chevs.. My truck compares real good. Even with my smaller tank and 35" M/T's I am still gettin equal or better then them all running stock minus a 01 chev with 33 BFG A/T. You just gotta learn the driving pattterns to get the most out of your fuel.. Keep er blow 2000RPM, light on the gas and don't let the Hemi and your right foot become best friends.
You will love your Ram.... I honestly only bought mine because I got at an amazing price with low miliage, 4x4, Hemi, and quad cab. But fell in love with it and don't think I could ever own a truck other then a Ram from now.. (minus a 2500 Denali HD for weekend cruiser