You are correct. It is a combination of both the short commute and cold weather. Last winter my wife drove our Prius to work (only a 3 mile commute one way) and our MPG saw a significant reduction from when we would drive on the interstate for long periods of time. But, this past Christmas on a trip to WI, despite we were on the interstate the 16deg temp. outside caused our mpg to drop from the typical 50's to 20's... I thought I was going to cry! Also, I don't know if anyone else has experienced this but, we are actually getting better gas mileage with more miles on our car. I don't know if there is a logical reason for this, but I am sure someone out there would know. Anyway, don't give up yet... You just need better conditions.

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