The Walking Dead & Gasoline?

That depends on the conditions you are storing it in and how man octane your engine needs.

Remember to fit a flame trap/arrester so you don't blow yourself up.

My great-grandfather bodged one together and had it rigged up on his work truck in WW2
Got arrested for starting it catching fire in the middle of Melbourne, he may also have been violently drunk

or propane

dr650 master race, mein neger

What do you mean "faked"?
As in built it himself?

I disagree. Although industrial manufacturing may end, the knowledge of how to build and maintain simple engines will not just disappear to thin air.

While wild cattle is extinct. There are similar animals like bison and water buffalo that could potentially do alright.