For one, don't run your autostart for long because that gets you 0.0 Mpg to factor into your fuel economy equation. Keep your car empty, no hauling around 6 cases of bottled water if you don't need to. Try not to gun it to get up hills, try to coast to red lights as soon as you see them, and use your CC on long hiway trips. Also keep a close eye on your tire pressure, it matters when your trying to get the best mpgs.