[hagcam]

I have found that I get about the best economy/ diveability at 65 MPH. At 55 mph it is too slow when you get to a hill and then it has to downsift right away. MPG did not really improve at 55 vs 65 mph. On a long trip I will average 8.5 m/imperial gallon ( 7m/US gallon)on the interstate, and 7.5 (6 to US gallon) on the smaller windier roads. I can do better on flat runs but I live in the mountains of the West Coast.
On a 3500 mile trip I will average 8.5 miles to the imperial gallon. (7n/USG)