The fuel gage, while the ignition is on, tells you about how much fuel you have left in your tank. If the level of fuel in your vehicle is low, a light located on this gage will come on as a warning.

Compressed Natural Gas (CNG) quantity is affected by changes in fuel temperature and fuel pressure. This may also affect the fuel gage reading. After filling up with CNG, the fuel gage may read past F (Full). After driving several miles, the gage may read a little less than F (Full). This "settling" of the CNG in the fuel tank is normal and does not indicate a problem with the fuel gage.