I have a plastic 5 gallon gas can. It's from a company called "Midwest Can" - they are pretty common. The first thing that breaks is the cap. It tends to split, so you can replace it with a printed one. It should be noted that ABS and PLA don't hold up to gasoline - I think nylon would be OK. I'm storing used engine oil in my container so I printed my cap in ABS.

This is a parametric design so you can adjust the size of it to fit your own application.

Features:

Knurled cap for a good grip.

Buttress threads.

Note: This is not OpenSCAD. It's a program written in Go. The main library and code examples can be found here:

https://github.com/deadsy/sdfx

About Go: https://golang.org/