Just thought I would post an update. I did a 5 day offroading trip last week and averaged 9 MPG(DIC and calculated) towing over 14,000# on freeways an mountain roads. Not too shabby, IMO.
Unloaded my truck is still pretty consistantly getting just over 13 MPG with mostly city(60%) driving. Unloaded on the freeway today, I was able to get 19 MPG over about 100 miles at 69 MPH. That dropped down to 14.5 shotrly after I got off the freeway, however.