Thank you for the replies.

Jason, when your engine shifts state is there a variation in the roughness (i.e. sometimes it is rough sometimes not)? And if so does the engine load determine roughness (primarily climate control on/off)? Have you every had the engine cycle on and off several times in quick succession (over the course of 2 seconds or so)?

Somtimes with mine it is barely noticeable and other times it is quite obvious. Generally with greater load (though not always) the engine will shut off more roughly.

Does anyone out there live in the DC area? It would be great to compare my car to another and I only know people with the Prius I which has a very smooth engine transition.

Have fun

Christian