Here are some tips we've come across. Feel free to add your own:

• Keep your tires properly inflated. Tires should be inflated to the pressure recommended for your vehicle; usually you can find this number inside the door frame or in your owner’s manual. For every three pounds below recommended pressure, fuel economy goes down by about 1 percent. Tires can lose a pound of pressure a month, so check pressure regularly, and especially before going on a long trip or carrying heavy loads. Also: Don’t buy “aggressive” tread tires if you don’t need them.