We have a 2012 30RE with 50amp service and two a/c units. Trailer weighs in at just under 6400 pounds empty. Our 2011 Ram quad cab pulls it great. Pulling in tow/haul mode we rarely leave fourth gear. This is loaded with four adults and fully loaded.
You didn't mention engine size or gear ratio. We have the 5.7 Hemi, 3.55 gears, factory tow package, and 20 inch wheels. The truck tows the 30RE very comfortably. We also have a 10k lb. equa-l-izer hitch with 1k lb. bars. This makes a big difference in drivability and safety. We average 11.5 to 12 miles per gallon. We are in North Texas. Most of our travel is in rolling hills. No mountains but never flat.
The two links provided in the previous posts should get you the technical information you're needing.
Hope this helped.
2012 Ram Longhorn Limited 5.7Hemi
Millie & Scooter (man's best friends)