Just got through the first tank on the Aveo. The result wasn't too bad.
This was all commuting back and forth to work. The speed limit is 55 and I did the speed limit. I time lights so I don't have to stop at them too often. I also coast in neutral down hills that I can maintain or gain speed going down. I accelerate hard, but shift to keep rpms low. However, the car did see redline (and fuel cut) a few times during the tank. Despite popular belief you can have fun and get good mileage.
This morning I tried a few more tricks on the way in to work just to see what I could get. My scangauge showed that I got 52.5 mpg on the way in. Not too shabby.