How would post-apocalyptic survivors get gasoline?

Assuming they don’t have access to a refinery like Mad max, how could they make gasoline?

They’d probably turn to ethanol instead.

Assuming we’re talking a small number of survivors type situation, siphoning gas out of the skeleton-filled cars littering the highways and then the underground holding tanks and gas stations ought to work for a few years at least. Your post apocalyptic battlewagon really ought to be a diesel though since underground stores of diesel may last essentially indefinitely and there are many more options for unconventional fuels. Plus you’ll need the extra torque to haul all that armor around anyways!

In Genesis II, they converted their cars to steam power, which could use a wider variety of fuel. And, they had horses. And a nuclear reactor.

Yup. You’ll need one of these

One of my favorite books, Earth Abides addresses this by having the main character take gas from stations where the electricity has not yet failed, and when that doesn’t work, taking gas from the depots at the edge of town. Of course, this book was written in either the 1940s or '50s, so stuff was a lot different then.

The OP is a non sequiter. To make gasoline requires a refinery. Period. It’s kinda in the definition. You have to refine petroleum to get gasoline. “Scavenging” does not equal “making.”

Modern Ethanol has a short shelf life. I learned quickly to use a stabilizer in my generator gas. Even with stabilizer Ethanol should be used within 9 to 10 months. A year max. Regular gas lasts longer but even it will go bad and foul the carb within a year without stablizer. Old gas creates a lot of income for small engine repair places because people leave a tank of gas over the winter or fill the tank from a can bought the previous summer. The varnish in the gas clogs the carb and the small engine shop makes money from the repair.

Diesel Oil reserves would last must longer. Underground Tanks at service stations would be an excellent source for post-apocalyptic survivors.

Ok, then ideas like the one about using steam engines.

To expand the question: How would people use machines after the gas runs out?

Could a vehicle be modified to tolerate bad gas?

You make friends with Mad max

I knew what the movie was before I even clicked it.

Of course, the hero used a methane powered motorbike, made from chicken-shit. As a chemistry-aware adult, I am no longer sure how he got from methane (anaerobic decay of fecal matter) to methanol (poured into the tank of his trailbike) without a serious chemical reactor system.

How did people use machines before gasoline? Steam, horses, slaves.
Horses were such an important source of power we named a unit after them.

I’d like to see the gerbil wheel they used for a horse powered engine.

Missed window: i was asking about running machinery that usually uses gasoline.

It might depend on how apocalyptic the apocalypse was. If the infrastructure is totally destroyed you would need to go back to carts pulled by horses, mules or oxen. If there are still plenty of resources left lying around, you could probably scavenge for a good many years, the rest of your life probably, because it wont be a long one.

Eventually whatever population was left would revert to a level that it could sustain. Water is a good source of power, wind too. They can be used directly to drive machinery, to grind corn for example, or indirectly to generate electricity.

A lot would depend on the circumstances of the survivors and how much effort they wanted, or were able, to put into this stuff, beyond just simply surviving.

Imho scavenging really depends on how many survivors are left. I used to work at a gas station, and they could store maybe 1k gallons in an underground tank. Maybe 10k, maybe 100k, but depending on how many surivors there are, eventually a given area would run out. Im asking about when all the old stores are gone.

I read quite a lot apocalyptic books and what makes me wonder is why bikes are not utilized more. Same goes for the moves.

During WW2, cars were converted to wood-burning vehicles using a wood-gas generator

Wish granted: Horse mill - Wikipedia