The only other difference I can think of is fuel quality/octane -- as mentioned. Do these people getting 300-400miles/tank live in other countries/areas where fuel is just WAY better?

Also, I looked around again. It seems consistent that the stoimetric point of ethanol is 14.1 (vs 14.7 for gas). That means, for 1 part fuel, it takes 14.1 parts ethanol for complete burn. 14.7 parts gas for complete burn.

Switch that around and it takes 14.7/14.1....about 1.0425 (4.25%) more ethanol than gasoline. But that doesn't count for energy difference (and the amount of throttle) necessary to roll the vehicle along. IIRC, Jerry Lemond was saying 10% loss -- which I thought was a little exaggerated. 5% is what calculations imply. If it's less than 2%, none of us should be getting much less than the 15-19mpg that was the EPA measure for the VX.

Actually 22gals x 19mpg = 418 gallons possible for a tank of gas. Obviously, that would be for a highway trip. It seems pretty bad that many of use are in the 250mpg range, don't you think?

Sorry for the ramble....