Joe,

Thanks for your answer. I'd also be curious to see how it works out on flat roads. With the exception of overpasses that's all we have here. I do find that if my SOC is high I can get that type of mileage in the 45 - 50 mph range, especially since the motors will kick in every so often to reduce the charge and thereby the work of the ICE. Perhaps the downhills causes your SOC to get high enough that that's what's happening to you.

Please keep us updated as to what you find on flat terrain. And if you can figure out what specifically to do and not to do will you offer a course.