I will read it. Thanks for the tip.
This is very interesting as I have had a similar experience but without the
abrupt change between good and bad pavement which could be noted. So, as a
result, my data are not as good as yours.
The Prius is a very finely engineered and tuned car. It is optimized so
every change from standard counts toward lowering gas mileage -- weight,
sttreamlining (such as adding a roof rack), tire pressure, use of heater and
cooler, etc. I've even noticed that wet or dry weather appears to change
the gas mileage a bit.
But, even at its worst (in winter with the heater running contiuously), the
gas mileage is still better than any other car that I have owned.