Sandy , That sounds real close to what we were figuring. We towed our 23 cross country with a Chevy Tahoe. I was a little concerned about the Tahoe's size but it had the bigger V-8 and a tow package on it and it did just fine. We towed 65-70 all the way but obviously it hammered the mileage. We went from 17mpg with the empty trailer, to usually 13mpg average (once in a while as low as 10 on grades). I had had a Ford 3/4 ton with a 460 and a 4 speed in the past. That truck would pull a house but I think back then I thought 10mpg was good if I remember correctly!!