First of all, I thank you all for your kind and informative feedback and inputs.

Even though I own a Prius, I don't consider my motive of having it is as noble as most of fellow owners here.

True, MPG performance is important, saving the environment for next generation is important, but, at the end of the day, I want to be able to make it home in one piece without any injury; at the end of the month, knowing I can afford the monthly payment without much struggle. It's the reality no matter what.

People around me consider me a freak ( nut ) because I know how many miles I drive in any given month, I keep track of my cars' MPG for years, I plot the best route to work, the shortest route, or the quickest route from point A to B. Most of the time, I know the distance difference between the shortest route and the quickest route.

To fully utilize a hybrid like Prius, optimize its performance, it will take time and mind. There are plenty of reasons why Operation Research in engineering department is required for at least 3 credits, and 4 credits required in math department. It's a serious business. In my opinion, in order to achieve excellent MPG, you very much require to have good knowledge of physics and math.

While we have Mr. Wilson supplying us with those detail experimental results and chartings, I still believe safety outrank everything.

Driving in low speed is not always safe.

Reading all the feedbacks and inputs so far, I am glad I have proved I am right.
That's enough for me for now.