I think it's a good idea. Maybe there could be an option to increase how quickly fuel is used, so it can be set to more game-like rates. For me, at the current rate, there's zero chance to run out before I get bored and/or crash into something.
Should be possible by making the app basically send the fuel command to the console with the variable (that you have to set for the command to work) being what you entered in the text field. Then again, I don't know how that would work, but I'll try using the fire debug app as a base for it and modifying it to change fuel levels.
I'm amazed that you have the skill to drive for so long that the car runs out. I usually wrecked it before it even uses 1/2 a litre of fuel.