I was going to go til I ran out of gas, which is what the needle said I was doing. But when it only took seven gallons, I decided when it gets down to the red line, I will begin to carry a gallon gas can, “just in case.”
I don’t know any other way to find out what the limit is on the mileage...”When it says “E,” is it really empty?” Not this time! LOL!
This seems like a logical way to proceed. But there are caveats involved.
First, it can be unsafe in some areas to run out of gas. Many vehicle react poorly to sudden loss of power, and can be difficult to wrangle to the curb. Also, it can be a needless or unwise stress on the engine and fuel-delivery system. Stuff gets sucked up into the lines and deposited where it shouldn't be. (It is particularly imprudent to do this in a vehicle with fuel injectors. Running out of gas is to be avoided under all circumstances with them.)
Fuel systems that used to operate as regularly as clockwork, with in-line fuel filters and mechanical fuel pumps have now been replaced by electric pumps mounted inside the fuel tank. Filters have been moved around too.
Fuel venting has become an issue. When replacing a fuel cap, make sure you get one that is designed for your vehicle. I have heard apocryphal stories of individuals using the wrong cap, and having the fuel pump empty out the fuel tank even though no replacement air was being allowed to enter. The fuel tank was collapsed by atmospheric pressure, and would subsequently hold only a gallon or two.
Other problems have arisen because of the use of ethanol blends. Some fuel system components were not designed to have to deal with alcohol, and having to replace a fuel pump because of government-mandated fuel changes does not mean that the government will pay for your damages.
You can measure the volume of your fuel tank capacity in other ways, but none are safe because handling fuel is not safe. The only safe thing to do is to inspect the fuel tank from the outside to see if it appears to be normal.
Carrying a spare fuel can is not necessarily a bad idea, as long as it is secured in a proper place out of the passenger compartment. Don't tempt thieves with an overlarge container, and transfer the fuel from the can to the tank when you're refueling; then fill the can and then the tank. That keeps the gas in the can fresh.
It means your car was pointing to the East. Of course, "E" always stood for "Excellent" in my book....