Low Fuel on Ion

What?

The light goes off as in LOW FUEL reads on the display? Or do you mean that the LOW FUEL actually reads earlier that it should while there is enough fuel in the tank? Or ones LOW FUEL reads it disappears from the read out early??

I assume that this was choice #2: "Or do you mean that the LOW FUEL actually reads earlier that it should while there is enough fuel in the tank?"

I'm not sure I understand what your question is, however: the light should come on before the fuel tank is empty, somewhere around 2 or so USgal, IIRC. You do not want to run your car out of gas, or try to run it on fumes. The gasoline acts as a coolant for the fuel pump, and letting the tank level drop below the pump (past E or after the light comes on, assuming the light is functioning properly) can burn up the pump prematurely.

-rj