Use the Cruise Control at every opportunity.
Anticipate the Stops and Lights and coast there. The sound of the 8 speed downshifting provides entertainment while you do this. Sounds great on my Sport.
I've had my Ram for over 2 months. I have a 23 mile round trip for work, 16 of it is highway cruise, 2 laner with the cruise set at 55-57 depending upon conditions. Some in-town driving during the week also. Weekends involve a trip or two out of town to neighboring or nearby towns.
I'm averaging 18.5 MPG. Loving it! Hemi, 8 Speed, 3.29 axle, Trifecta bed cover.