EPA Mileage numbers are next to impossible to attain in real life. I remember reading an article on how they get those numbers. They have no accesorries on and don't drive more then like 45 or 50 mph.
If you want to improve your MPG you have to be reall good about checking your Tire pressure. I would say put in 2 or 3 psi more then what is on the tag in the door jamb. Also if you can reduce the weight of the car ( unsprung weight works the best) it will help with your MPG. Just some hints for you(you might have thought of these already)