Thanks for posting this, MetroMPG.
That speed vs. MPG graph pretty much mirrors my experience with my Mustang. Most performance car enthusiasts ass-u-me performance cars have a "sweet spot" around 75 MPH. That just ain't so with modern (efficient) fuel injection systems. In my experience, the best FE is at the lowest speed in your top gear. In my case, about 35-40 MPH.
And it's interesting that most people can't believe that a performance car can get fuel "economy".
According to EPA's 2008 estimates, I should be getting 17 City/ 25 Highway/ 20 Combined with my Mustang.
The worst I've ever gotten was .02 MPG under EPA Highway. (24.98) And that was because I ran it in the garage to charge the battery (at ZERO MPG) during the Winter.
According to ecomodder.com's criteria, I've never
not been a hypermiler with my Mustang.
I'm getting better fuel economy with my Mustang than a lot of people get with their 4-cylinder Camrys and Altimas.
A major part of it is the "nut behind the wheel" and route planning.
As they say, YMMV.