Well, I just personally purchased a 2013 Ram 3500. I live in the Pacific North West, so plenty of hills and mountains and some flat areas. I plan to purchase my RV in about 2 years, just laying the groundwork with this truck. My last tank pulled 18.96 mpg for mostly freeway between Tacoma and Portland on I-5 round trip. I only had 1200 miles on the Odo at the time, so the engine is still working itself in. First tank was 17mpg and the second tank was only 15.6mpg, but the upholstery shop idled it for 5 or 6 hours (saw it on the hour meter) so I know that played into the sorry mileage there. I'm expecting to see 18mpg or better as a daily average for work commute and possibly low 20's for the longer distance road trips.
