I've never really considered its formula, but I always kind of considered fully synthetic oil wasn't made from crude oil/dino goo. But apparently it's usually still the primary ingredient.

So there you go.

I also haven't ever done an oil change on my own car and .. only actually topped up oil maybe once, so it's also never really come up.

I had to top up engine coolant in the car last year because it was complaining (about 6 weeks after the car's first service, fuckers) and had to research what the fuck to even put in it, because it was good friday on easter long weekend and I couldn't just drive back and say "fix my car" and I had to drive.

I really know fuck all about cars these days. I couldn't even tell you what my car's engine looks like. I've only seen it that once.