We have 4 4.7 and 3 5.7 all 2009 SLT QC All towing package with LS diff no mods except for K&N drop ins
We get an avg of 14 to 17 city and 18 to 22 hwy mpg on the 4.7s
We get an avg of 9 to 13 city and 15 to 20 hwy with 5.7s
Hate the MDS, it is useless except on level highway runs and we had to replace some plugs on all the hemis , none on 4.7s
All tow the trailers we drag, and all carry the bed loads of tools and parts, appx 700 to 900 lbs all the time
The mileage drops using the trailers on all trucks.
Advantage 5.7 step on gas it moves, but it burns the gas, tows trailers better, but we only use trailers about 20 to 25% of time
Advantages 4.7 better gas mileage overall
We like both versions, but my persoanl one is the 4.7 by my choice, I don't need the extra hp, and I am very happy with my mileage.
All mileages were calculated, not using the ECU
RAM 1500 SLT QC 2009 INFERNO RED, ARE Lift Lid ,Spray on Bed Liner, K&N Drop In, Pioneer DEH P8400UB, Alpine Amp, Mopar Kicker sets in all doors and dash, 2 Polk 10" Subs, Polk AMP, SteelCraft Nerf Bars, Mopar Fog Lights, CalTrend Seat Covers, WeatherTech Front Mats, Putco SS Fender Liners, SuperBumper SS Hitch Step/Impact Absorber, Onki Aegis SS Center Guard, PIAA 2100 driving lights