the problem is on gas tank
the problem is on gas tank and cold winter driving. cold cause the weak of battery, you'll see 30% drop on mpg in winter on hybrid cars, it's normal. People like 40 mpg all year long, but the fact is 40mpg only before winter. 325 is a little low, because gas tank is not full, you only filled up 10 gallons vs 14 gallons full. I told other guys, when you hear pump click 1st time, don't push more gas in, if you push more, you'll hear more click sound, that's really bad to the car. Take pump out a little to the edge of filling port, then fill in more, you can still fill 4 gallons more from 1st click, make sure no click sound anymore, and watch pump meter closely, don't overfill too much, 3 to 4 gallons are ok, 5 gallon is too much. then you'll get 450 miles on a full tank in winter, then 550 in summer. give it try, then let me know.