I get the same noise on my 2010 Prius (and, by the way, we get 49.6 MPG average over 17000 miles) - My thought is that it has something to do with the electric motor - I hear it intermittently, both when applying the brake, which would activate the electric motor, and at other times (I've changed the display to show graphically the hybrid elements that are active in hopes of narrowing the possibilities for our next trip to the dealership. My concern is simply that this screech may be symptomatic of some problem that will manifest, and want to register my complaint in the event that this becomes a fact in order to hold Toyota's feet to the fire in that eventuality. With regard to your mileage: one must drive a Prius differently than one drives a Grand Caravan - jack rabbit starts are a "no-no", and coasting to a stop sign or a stop light so that using the brake is used only to complete the stop, using the Jake Brake (B) to slow you down rather than using the brakes, cruising at 65 MPH, rather than 75 MPH will combine to deliver the "green" feeling you seek.

Hello,
I just got my new Prius 2010 Blizzard Pearl 3.
So far I find it fun to drive and easier to manage than my Dodge Grand Caravan.
However:
When dirving I hear this high pitched screeching noise. I took it to the dealer and he heard it too. He said to bring it back at 600 miles. I would like to know if anyone else has this problem.
Another problem is that I am only getting 37.9 miles to the gallon city driving in Seattle. I use the eco mode exclusively but I do use the fan on hot days. When does one hit over 40 miles to the gallon.
Anyone have any suggestions? I am getting disappointed on having spent $27,000 on being green. When does one start feeling green?