I have a Ford F250 with the 6.0 liter diesel. I get about 15 m.p.g. on the highway with just the boat if I keep the speed at or below 75. I usually tow a 27-foot 5th wheel (maybe 8,000 pounds) with the boat behind that. It's reasonably comfortable and is a four-door so I can carry the family or crew and still have lots of room for gear. I drove it to Texoma and got 9.5 to 12.5 m.p.g. at 70 m.p.h. It has trailer brakes so control is really good, even with the train, and power is never an issue. I can go way faster than I'd ever want to with all that stuff hanging off the back and I can still pass pretty easily. Without anything on it, I get 21+ on the highway and 16 around town.