I think I am starting to understand why people with the news diesel trucks get lower mileage than my old tuned up 2001 Dodge/Cummins! They are towing much faster!!!!!!!!!!! If I towed 70 I would be down at 9-10 MPG vs the 12.2-12.5 that I average at 63-64 MPH!
And at the end of the day they have saved 24 minutes, based on a 250 mile day comparing 63 MPH vs 70 MPH all other things equal. 3 hours and 58 minutes vs 3 hours and 34 minutes. There are other variables that might get the toad there before the rabbit!
Chris