I had a 2007 quad cab 5.7 hemi 2500 with 3.73s (I think) that I used for a good many years. I towed a 24' box trailer with my car (3000 lbs, 4 wheeler, and tools). It got the job done, but you had to work it. I have 3 inclines on my way to the track, by most standards they are just small bumps, but they let you know how well your tow rigged does on a hill. I got 8 mpg towing with that truck and 14 mpg everyday driving. My dad has a 2005 single cab 5.7 with 4.10s and he gets 10 mpg doesn't matter if he's towing or everyday driving. My 07 was my daily driver, but than I bought a beater for everyday driving so I bought a 2017 6.4 Hemi with 4.10s (Still has the 6 speed trans) for towing and such. I went with the 4.10s since I wanted more power when towing and from research I did it seemed the 4.10's got MAYBE 1-2 mpg worse than the 3.73s. With the 2017 truck I get 10mpg towing and 14-15 mpg everyday driving. It has WAY more power and tows so much better than my 07. I bought the truck in March 2018 and only have 11,000 miles on it so I haven't really broken it in yet. I wouldn't hestiate getting the 4.10s esp since they have I think an 8 speed trans now, that should help with gas mileage.