I suggest buying one or more 5-gallon plastic gas cans.
They cost about $9.50 or $10 at Wal-mart.
When there are gas shortages, major gas price spikes, etc. you'll want to be able to get extra gas -- and let me tell you: there will be no gas cans available then.
The smart people get gas cans BEFORE you need them. It would only take a 1% increase in "gas can demand" to clear out Wal-Mart's stock. Remember, all the big stores do "just-in-time ordering" so they just have enough for a few days' demand.
The first thing to sell out in a crisis (or one of the top 100) is gas cans.
You don't have to fill them right away, because gas goes bad after 6 months or so. But you can use it in your car, and cycle it. But at least have the gas CAN on hand.
And if you want, you can fill a couple of them at $3.50 a gallon, and fill your car with them when gas shoots up to $10 a gallon (or more!)
I will remind all of you: most Traditional Catholics don't live within walking distance of the Holy Mass. No gas means no Mass -- which is why this particular "material prep" borders on a spiritual (=more important) one!