Mazda offered a trip computer feature on 2006-2007 Grand Touring models of the popular Mazda 3. Fortunately for owners, the trip computer is equipped on every trim level of the vehicle, including the base model sport. Unlocking the trip computer will display average fuel economy, instant fuel economy and miles left until empty.
Get in your vehicle and hold down the “Am/Fm” button on your radio without cranking the engine.
Keep holding the button and crank the engine. After a couple of seconds, your dash radio display will say “Dis On”. Turn the engine off. Release the “Am/Fm” button and turn the engine off.
Crank the engine again and press the “Set” button. Your average fuel economy and current fuel economy will be displayed. Press set to toggle through the features. The system also tells you how many miles you have until the tank is empty. Press “Clock” at any time if you want to return to the clock display. The setting will be on every time you drive your car.