I know this is similar to another topic. I bought my Prius new (8 miles on the odometer) and I have not seen the overall milage go above 37 mpg since then. I drive both city and highway miles. I live in Florida so I don't have to worry about it getting too cold. I do drive a bit aggressively, but I should be getting better milage than this. I do come to a slow stop when possible. I'm not sure what I am doing wrong, but a friend of mine who has had the Prius for years told me she has never seen her MPG drop below 45. Being so new I haven't had an oil change yet.