I'm still waiting for my Prius, but I love to play with numbers. From global MPG posted here I've made some considerations: 1) three out four posters with more than 15,000 miles have significant higher MPG ( more than 58 MPG ) 2) average MPG (for posters with less than 6,000 miles) is 47.6 MPG with a minimum value of 41 and a maximum of 54,6 3) Not depending on temperature, from these data, there is a 90% probability to get MPG between 42.2 and 51.9