I use to own the v6 and I can honestly say that the Hemi get much better fuel mileage because its not trying to lug around the huge chassis and body. My V6 would avg about Mabye 13 MPG while my Hemi can get about 18 to 24 on good days sometimes even better.
see full Ram 1500 review
2011
4dr Crew Cab 5.5ft bed 390-horsepower 5.7L V8 5-speed shiftable automatic 4WD, part-time w/low range
I am fortunate in that I work from home, and do not need my vehicle to commute to work. However, for a six month period I made a 40-mile round trip five days a week, and averaged 15MPG in mixed urban surface/Interstate driving. This is considerably better than the 2007 Jeep Grand Cherokee 4wd/4.7L V8 the truck replaced (13MPG), and I attribute the better performance to the MDS cylinder deactivation.
I have observed 22MPG over a 400 mile trip of combined Interstate and rural 2-lane highway travel with speeds ranging from 60-75 MPH. The truck was unloaded at the time and acceleration runs were gentle to maximize fuel economy. The return trip resulted in19MPG performance over the same route.
see full Ram 1500 review
2012 Ram 1500 Gas Mileage (MPG)
Unlike other fuel economy surveys, TrueDelta's Real-World Gas Mileage Survey includes questions about how and
where a car was driven. So you can get an idea of the Ram 1500's
real-world MPG based on how and where you drive a car.
What Our Members Are Saying about the Real Gas Mileage of the 2012 Ram 1500
5-speed shiftable automatic RWD
5-speed shiftable automatic 4WD, part-time w/low range