I've beeen thinking about this for a while, but am hampered by a rather poor knowledge of physics, compounded by the hybrid drivetrain.

My original desire was to try and gain a handle on the optimum RPM range of the Prius II ICE, since people in the yahoo forums have stated that there is a pretty flat efficiency curve between 1500 - 3500 RPM, but I disagree based on my experience. I also think that the plethora of jokes about slow hybrid drivers confirms my impression, aerodynamic considerations aside (otherwise why crawl up a hill ?)

Not too far from my house I have an uninterrupted stretch of road with about a 500 foot elevation over 3 miles. I am thinking about running that stretch between 30 and 40 mph in 5 mph increments, starting from middle battery SOC, and see what kind of MPG I get. I can estimate the MPG effect from the wind resistance from Wayne Brown's Palm program.

Any advice to improve the method is welcome !