So far I have 2,500 miles on the car. I've avg'd about 27.5 mpg mixed city/highway. Usually drive about 75 mph on the highway. I shift at about 3,500 - 4,000 rpms. Does gas mileage improve with summer gasoline and as the car ages? Right now, I'm getting the city avg from the sticker, which isn't bad at all considering how I drive.