First and foremost, make sure that your tires are properly inflated. This is probably the number one robber of gas mileage. Another great way to get better mileage is to make sure that your car is properly tuned. It is far better to get some good gas mileage than the dump excess gasoline into the atmosphere. It is better for the environment and your pocket book. When you are at a stop, do not start up and gun your engine and take off. This is bad for your mileage and your engine as well. On a highway, use cruise control. The constant pressure of your foot and then the lack of it on the gas pedal will waste a lot of gas. Excess weight can cost gas, also. The heavier an object is, the more energy it takes to move it.
See your dealer for more tips about getting extra mileage!