I was reading in a prior thread about the gasoline tank bladder...and that the amount of fuel you put into the Prius can vary. I did notice this with my new 2007. When I filled up with 6 bars gone one time I filled 6 gallons the next time I filled 4. If the amount of fuel you fill your tank with keeps fluctuating how can one accurately figure the gas mileage? Do you believe the computer on the consumption screen to be accurate?