I find that I am a prepper. Not a survivialist, but a prepper. (A survivialist is a nut worried about the end of the world as we know it. A prepper is a rational person worried about bad things happening to them and their neighbors)
Because i'm a prepper I keep a 2 gallon "can" (plastic jug) in my trunk full of fuel. When I fill up my car, I put the jug in the car, re-fill the jug, and top off the car. That way the gas stays fresh.
But why?
For several reasons: I might run out of fuel. Having a small amount will get me over 70 miles, and on the east side of the mississippi, odds are you will find a station that is open.
Someone else might run out. This happened today. A man pulled into my driveway to get out of the street, his car sputtering. He was out of fuel. The gas station was two blocks away...up hill. (of course) I popped my trunk, put a gallon or so in his car and he was on his way. He was the director of the Narcotics Anonymous program at the Church a few miles down the road. With what I gave him, he could make the meeting on time and then get fuel.
A survivalist will have 500 gallons of fuel buried in a tank in the woods, and would not give anyone a drop. A Prepper will have a few gallons on hand near by so they can help themselves or others.
(don't fear that the can will blow up if you're rear ended. You have 15 to 20 gallons in the trunk of your car normally, called a gas tank. Do get a tight fitting cap or the fuel will vaporize and make your trunk smell.)