Hi HG,

Wayne Brown is an engineer/scientist/tinkerer type who was active in the 2004-Prius Yahoo group up until last year. He contributed a Palm program that estimates MPG for a G2 Prius based on conditions entered. It is astoundingly accurate, reflecting a ton of empiric measurements that the author collected, as well as physics modeling quite above my head. From elevation to tire resistance, it's all there, and can be changed at will.

addendum: The program also shows the breakdown of power requirements for a given set of conditions, which I find terribly interesting and useful. It is from this that I can gather how much additonal energy is being consumed at higher speeds.

So far as I know, it has only been written for the Palm PDA. Macintosh has an emulator that can be used in a pinch.

I'm pretty sure I have a zipped file I could send you, and Andy Roberts has the file hosted on his web page. His URL can be found by searching the 2g-Prius yahoo forum