Besides being a fun piece of fiction from Chord, this is a good question to ask yourself when you get a new (to you) vehicle. Most cars, trucks, and motorcycles have a small reserve of fuel past where the guage reads empty. You can either try to calculate the reserve based on the little book in your glove compartment or you can pack a five-gallon fuel can and go for a long drive.
I just got home yesterday from a 12-hour drive from Colorado. The stretch from Limon, Colorado to exit 252 in Kansas is theoretically outside of my fuel limit according the fuel gauge on the dashboard, but I know that there is a 54 minimum mile reserve available. It takes 22 of those to make the stretch I drive. I like the food and fuel station at 252 (the Pilot or Flying J), and it's usually the best price.
My wife actually found the reserve because she was driving my van in Texas and was searching for an open gas station. I will admit that butt cheeks get tired of getting clenched while you keep an eye on that needle going further under the "E". If you know the reserve, you'll know if you can get someone delivering a child to the emergency room without stopping at the Kum and Go to fill up.
Iron Noder 2017