figured i'd share my 5k break in story... As i posted here a while ago, i recently moved across 5 or so states. during the trip, i was averaging about 33 MPG at highway speeds with a kayak on top. I figured, not bad, it's still better than my old car did without a kayak! anyways, i'm now up to 5k miles, and took a trip up north for the extended holiday weekend (got monday and tuesday off!). of course, i took the kayak with me on the trip, and we were traveling at about the same speeds (70 MPH) for 95% of the trip. well, on this trip, i managed to average 43 MPG! i just find it remarkable that my milage can increase so dramatically over just a few months. and yes, i know it's a little warmer now, but moving was a 15 hour drive, so i figure the car was plenty warmed up during 99% of it.
There is a learning curve during the first 5000 miles of driving a Prius. Looks like you learned how to drive it better.