And you can't always tell by looking if your tires are under-inflated.
Every car has a sticker on the door post or door jam that tells the manufacturer's recommended tire pressures. Get a good guage and go fill up.
Here's a great
narrated video from E-How, a fantastic site for learning how to do everything, showing how to check your pressure.
Also, empty your trunk. If you are lugging around 50 extra lbs back there, you're scamming yourself. (Teachers and Mafia Guys, this could easily be you!)
Also, check your spark plugs and air filter. Or, to be honest ....
What really works for me is
PS: Most sources say that traveling at 55 miles per hour will give you much better mileage than 65-70 miles per hour. For more tips like that one, go to Fuel Me Up.Com
Read more Works for Me Tips from Shannon and join the fun. Thanks, Shannon!