1988 27' Jamboree, 460cid, 4-barrel carb, run between 60-65mph.
During summer, tow 3 watercraft (2-seater, 3-seater, stand-up) along with 8 additional 5-gal cans of fuel; probably close to 3000lbs. 6.5 MPG.
During winter, tow 20' enclosed trailer with 4 ATV's & 1 motorcycle along with 5 additional cans of fuel; around 4000lbs. 6.5 MPG.
It is what it is, I don't do this because it's economical, and the difference between 6.5 MPG and 7.5 MPG? Not worth losing sleep over; I burn more fuel in the toys once I get there than I do in the MH getting there.:W