I bought an 09 Ram with the 4.7 V-8. This truck had difficulty pulling an 18 ft. travel trailer in Colorado. It would run for miles over 4K rpm to maintain 60 mph on I-25. Traded the 09 for an identical 10 with a Hemi. No trouble pulling a 20 foot travel trailer or a flatbed with a Jeep and 4 wheeler. Lots of power. Gas mileage is slightly less with the Hemi, about 15 city and 17 highway vs. 15 city and 18 highway for the 4.7. A trip from Oklahoma to North Carolina averaged 16.8 mpg at 75 mph. Drove into the wind both ways.
Love the power of the Hemi. I have had many comments about the Inferno Red and the 20 inch wheels. Seats are very comfortable with the lumbar support. Best ride of any truck out there. Very quiet except for the subtle rumble of the Hemi. This truck is about to win me over from Chevrolet.
Fuel mileage does not come near the estimates or the mileage I would get with a Chevy 5.3 V-8. Power folding mirrors would be a great option.