I saw an interesting graph of MPG/Speed for the Prius in another post. I think it came from Japan. It is very informative and shows a sweet spot at about 43 miles per hour yielding 85 MPG. Anybody knows if anything like that exists for the CH?

Measuring average MPG at different speeds is not a simple matter. Factors like wind speed and direction need to be accounted for. In test runs a vehicle would normally need to drive BOTH ways to cancel out terrain unevenness and wind effects.

So, until we get more scientific data on real MPG at the different speeds for the CH what is your take of optimal cruising speed? (Highest speed and MPG - no tricks, constant speed).

Not that you can cruise there often but at 42 miles per hour you are able to maintain high FE driving alot. Unfortunately that is too slow for interstate or even rural driving. On vacation I did find that I could set the cruise at 52 miles per hour and maintain a 45 mpg rate.

At speeds where the ICE cycles on and off I don't know. But it seems to me that once I reach a speed where you're running on the ICE (45 miles per hour and above) that 55 seems to be about optimum.

I get the best mileage at 40 miles per hour (+/-) which gives me a small buffer before the car will run the ICE all the time (about 42 miles per hour)