My tow rig is a 95 F-250 4x4 Extended cab long bed with the Powerstroke. I have the Diablo extreme flip chip, 4" straight exhaust, 3" down pipe, Homemade K&N filter charger, full gages,4.10 gears,315-75-16 BFG-AT's, 28gvw B&M super cooler, E4OD with the TransGo HD-2 shift kit. and some other small diesel mods.
Oh yeah tomorrow I will be putting the trans back in with a new Billet HD converter. The truck has 191k Miles and stills runs pretty good. Empty when I dont have my foot in the kitchen i get about 18MPG (usually around 15).
The last towing trip I had my 8' pop-up pickup camper in the back plus the 16' car hauller and bronco going down to Kentucky and got and averaged 14-15 MPG.
I get better MPG when the camper is in the bed of the truck.
Here is a pic from Canada when a few of us went, I seen Grand posted a pic of his rig going around this wash out right in the middle of the road. All of us made it around with the exception of someone
who got stuck but i wont metion any names. This is with my old rig