Things that can have some effect are tire pressure, I like 50 psi, gas, I use premium. If you had tires that weren't Michelin and went back to Michelin Energy Savers A/S V93 and also with temps going up, so will your MPG's. Here is a link to all things that can improve MPG's:
Paul
Thanks for your effort in writing this piece. I have tried to follow as many of these high-mileage tips as I can within the confines of inner-city driving in Philadelphia. One unintended consequence of learning new driving techniques, however, is potential family discord. My wife's attitude is "just get in the car and drive"- when I am sitting in the passenger seat, I have to suppress my urges to recommend driving techniques to improve fuel efficiency. I have been married long enough to realize that there are some battles that are not meant to be fought... Cheers