[20after4]

Gasoline has a very short shelf life.

[zahlman]

Every source I can readily find puts that shelf life in the range of several months - so, not relevant to the scenario being discussed.

[x0x0]

Stabilizers for 20 gallons cost under $10, allowing 2 years of storage.

[devilbunny]

And gasoline is insanely easy to replace if you have a car that uses it. Drive to station when car is empty, dump oldest 5 gallon can of fuel into tank, finish filling tank, refill can. Do it every three months. No gas is more than a year old, half the time that stabilizers allow.

If disaster strikes, you never worry about the gas you have.