It's interesting to note the difference between the first half of the gas mileage (with my previous employer) and the second half (with my current employer). It averaged about 23mpg before, but of late it's been averaging about 29mpg. I suspect that there's two factors at work here: amount of highway driving and how often I floored the gas pedal. While I was still figuring out the car, I used to do a lot more of that.
I do so love my car. 8)