Your problem might be mds think about it if your truck is mainly only using 4 cylinders to push that hog it is putting a strain on itself and using more fuel. Since I turned mine off I am getting 14.8 and was getting 9.4 on a good day. My truck is leveled 3 inches on 361350 superswampers with CAI and bully dog gt tuner, flow master 40 series ect. Besides all the mods I knew I wasn't going to get great fuel economy but seance I shut it off and am using all 8 cylinders all the time she has better throttle response and isn't hunting for a gear all the time. And also she doesn't have to drop a gear to climb hills she stays at a steady rpm and speed

 

I'm in WPA too... wife remarked the other day her gas mileage in the 2011 GC dropped a couple mpgs... I checked my 04 Ram, same thing. Weird thing is, she switched to Costco on the last tank and its back to normal - about 19 mpg around town.