Howdy! I'm a hypermiler in North Texas, and I'm working on a book on the subject. I'm by no means an expert, or even an advanced hypermiler, but I've managed to improve my mileage by about 50% above the EPA standard, so I'm satisfied that I've got something to contribute.
So here's what I'd like some expert consulting on. I'm going to divide three chapters up into Basic, Intermediate and Advanced techniques, all related strictly to driving practices (the engineering and mods will be covered separately). Also, drafting doesn't fall into those chapters (see next question).
I'd like comments on the following. I find the whole drafting thing dubious. Based on the experiments on Mythbusters and my own experience, I find three factors severely limit the efficacy of drafting behind a truck:
1. Getting close enough to make a significant difference requires continual braking and acceleration, which offset much of the advantage.
2. Falling back to a distance that doesn't require #1 reduces the efficacy, and often invites a car from another lane to cut in front of you, causing you to fall further back, etc.
3. Trucks often drive faster than the speed limit, so whatever gains you make are offset by the increased resistance of your faster speed.
All this, combined with the safety problems, leads me to recommend against it altogether.
High revs - low gear vs. low revs, high gear. I've gotten conflicting information on that.
On the 2 vehicles in my garage, the FE improvements were attained with little if any drafting. After seeing some debris thrown into a vehicle lately (everyone was OK, thankfully), I'm really cautious of this practice with trucks. Cars are too unpredictable and stop too quickly to consider. After much consideration, I can't recommend it.
IMHO, each chapter should be broken into 2 categories: modifications and technique. From Novices to Intermediates, mods can account for a good foundation. Technique of all sorts carry the rest.