I was at 12.5 towing the XJ to and from R&V, avg. about 16-17 in the summer mixed driving. I have owned a few PSD's and never seen better than 18-19 Hwy. No way anyone gets 25+ unlesss it is all downhill.
Cheap Thrills Off Road
2003 F-250 4X4 7.3 PSD Crew Cab