I have a 2003 K3500 Crew Cab DMAX pulling 15K# 34' HitchHiker 5th wheel (12'7" tall).
Driving around Florida at the moment and played around a bit with speeds one day (it was a LONG day) on some back roads and recorded the following:
mph mpg
45 13+
50 12-12.5
55 11.5-12.5
60 10.5-11
Temps were in the 70's, winds calm, alligators active. Hills? What hills?
Last June I pulled a 16,000# 28' Wells-Cargo gooseneck out to Seattle (from St Louis) and averaged 8-11 MPG, lower (the 8) in the Rockies.
64K miles in the last 2 years and I figure I just about broke even now on the extra cost of the diesel engine.
My mileage is about double my Father's Ford V-10 gasser. No wonder he has to sit at home
Oh yeah, Banks Stinger package, with the big exhaust and exhaust brake (all self installed) and working well, thank you.
2003 K3500 Crew Cab, Banks Stinger Pkg, Exhaust Brake & Exhaust, OilGuard Bypass filter, Lube Specialist Secondary Fuel Filter, Allison Deep Pan, TTT Mirrors, B&W Turnover Ball and Companion Hitch, Truck Trunk Sliding Box and V-Box, LINE-X, Co-Pilot Live GPS, Hitchhiker 31.5 LKTG 5th Wheel 28' Wells-Cargo Gooseneck Car Hauler