Pg 36 of owners manual:
When the fuel tank is full, (6 segments) in the fuel gauge are displayed and then , (+) is added to the numerical value of the cruising range.
The range display will vary every time you move the throttle, less when you increase speed and more when you let off of it. A good way to see who much fuel you have left is while holding the throttle steady, push the button to display CURRENT MPG, then push to display RANGE, If you are getting 45 MPG and have a range of 90 miles than you have about 2 gallons left. But you must hold the throttle steady when your doing this.