So using your analogy, if 20kms could be somewhere between 15 & 30, 10 Kms could be between 5 & 20 and 5km could be between Zero and 15 Kms.
Not sure which one I would trust the most, 5kms to go, or a Low fuel warning?
At least if I see the Low Fuel I know to get to a servo ASAP. If I read...