So it was 70F today (brief warm-up) and we were 1-pip, so good day to demonstrate it may not be cold temperature to blame for lower fill-ups in winter. And the answer is: 6.8 gals went in. We are getting around 40 MPG with shorter trips, so that works out to a lack luster 272 miles per tank here in winter. I am thinking winter fuel has something to so with it, related to Gen2 gas tank design.