[jcp123]

Some of my best mileage was drafting a truck at about 68-70mph. 50.75mpg from here to Fort Worth, over two hours' drive. And only one hour of that was behind the truck! I think I had it up to around 52 or 53mpg when the truck made its exit. Another time I made about a 50min trip to tender an application for a city job, up and down that highway there are plenty of trucks and a lot of 55-60psl. It's been a while now but I recall getting up to 56 or so mpg.

Highway driving, I use a constant throttle rather than constant speed, although about 40 min out from here towards Dallas (my usual destination when I'm on the highway) it flattens out enough that cruise control would probably work almost as well.