I drive my Focus like an old woman. Slow starts and gradual stops. I have 23K on it since June. I do mostly highway driving. I stay up with traffic on the highway. A cop once told me a tip for not getting a speeding ticket "Only pass as many cars on the highway as the amount of cars that pass you" Meaning don't poke along in the slow lane but don't have the hammer down in the fast lane either. So having said that on the highway I would say I average 10mph above the speed limit. I average a combined 34 mpg's. My total commute is 95 miles per day. 85 on the highway and 10 on local streets. Add to that a couple of local miles at lunch.
I am very happy with the MPG's I am getting.