Late last week I finished my first tank of hypermiled gas. Using the techniques I described in a previous post, I managed 38 miles per gallon. Unbelievable. That's a 20-30% increase over the standard mileage.
The biggest lesson learned is how far the car will really coast. When you take your foot off the gas, the car keeps moving for quite a distance without slowing too dramatically. I've become almost obsessed with seeing how far I can coast and avoiding the brake pedal whenever possible. It's to the point now that I cringe at drivers ahead of me who use their breaks every time they see another car move.
Nevertheless, it's a driving style that I intend to continue. If you haven't tried it yet, do so. I think you'll be pleasantly surprised.