43 from a pickup!
I've seen 55-56 MPG at just 35 MPH in my car, but at 55 mph in 100F weather I can only hit 40 MPG on a good day. I'd gladly trade in some of that city mileage for a few more MPG on the freeway. I'll have to make it up with aero-mods.
The first tank I hypermiled I got 35.5 MPG and I was ecstatic. Now, if I can't get 50 mpg to work and back I'll be upset. When the cold weather comes I'll be a gas grinch.