Ya know, folks, the fuel mileage we all get is inversely proportional to the throttle-foot pressure. Getting high fuel mileage requires restraint and SKILL.
SKILL? Yup. Some of us pump the throttle and are hardly aware of it. Some of us are paranoid and brake and then accelerate at EVERY LITTLE change of speed of cars ahead of us.
So be easy, smooth, and steady on the throttle and watch your fuel mileage go up.
BTW, I have a Porsche Cayenne Turbo. I drove it about 300 miles a couple weekends ago, level freeway, about 70MPH (which definitely was in the bottom thirdtile of speeds), used the cruise control most of the time, and got just 17.0MPG, and that's using premium, too. I'll be buying my Edge soon.