[Flakbadger]

I've gotten great results in my car, extending the "glide" phase with very light gas pedal pressure... IE, getting up to 65, then slowly decelerating to 50ish. The glides last almost forever and I can easily break 100 MPG the whole glide portion. I don't know how flat your roads are, but I have gotten my best results (and least stressful for me!) by just watching the lay of the land, and using it to my advantage--that is to say, "gliding" with light power up hills, then regaining lost energy on the downhill portion.
Even moderate slopes on highways give great results. My highway trips are usually 50MPG+