I do not own a 6.4 but did buy a new 2012 Ram 1500 4x4 Longhorn with the Hemi. It has been flawless thus far. Does 20-22 mpg on the highway, 15-17 in everyday driving.
The 6.4 is a breathed on 5.7, and the 5.7 has been a good motor for Chrysler so I would expect good reliable performance. I have read reports of 18 mpg on the highway and 13-15 town driving with the 6.4.
Let us here at the fire know how it works out for you. Best of luck and congrats on the new ride!
