New prius owner for about 6 months, Fuel Cons was usually around 45-50 when I first bought it, now its considerably lower consistently.
Cold weather & short trips kill mpg in all cars- you notice it more in the Prius because of the in your face CONS display. Come spring your mpg will climb again.
Please read this item, and post as many answers to it as practical, to this thread: Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new See also: Why mileage gets worse in winter This graph shows the seasonal MPG swing of my first Prius over its first two years:
Love your graph: GreenHybrid.com was a treasure until the subsequent owners killed the database that prompted for temperature. But with the original data, I made these charts: WARNING: polynomial trend lines can 'average' data but also lead to misleading understandings of what is going on. Here are more traditional average and standard deviation examination of the same data: So why does my MPG dip when the weather is more temperate? Hypothesis include: taking shorter trips and getting out of the car; dropping the cold-weather warm-up pattern and removing radiator air block prematurely, and; suggestions? Other Prius from the same GreenHybrid.com database: It is not just me. More recent data from our first Prius: The fall-off at higher temperatures has to do with the heat-index. Up until about 80-85F, I can drive with the windows down and air conditioner off. But above this temperature, the air has to be dry to adequately cool the driver so the air conditioner is used and the engine driven compressor requires energy. The slope below 50F also approximates the increase in air density as a function of temperature. Bob Wilson