> Would that little spark be enough to ignite the vapors?

Yes.

> Gasoline...has a flashpoint of minus 43°C. Sparks and static electricity can easily ignite gasoline fumes.[0]

[0] https://www.skybrary.aero/articles/ignition-fuels

Good to know! I have a little tic of grounding myself before coming near the pump handle so I guess I'll just keep doing that.

A few years back Richard Hammond (the short former Top Gear UK) presenter did an experiment with this on another British show of his called Braniac (a sort of light entertainment popular science show) where he filled a caravan with petrol and fumes and attempted to get it to ignite through static electricity (they did lots of different ways of generating it).

They couldn't do it and even when for the laughs they decided to blow it up with a match it still didn't ignite.

The fuel air density has to be a certain ratio. This is why you have complicated systems to inject just the right amount of air and gasoline into the pistons. I would guess that since it is much harder to combust liquid gasoline is would be much harder to combust a very heavy gas/air combo.

Probably best to not use entertainment shows as a metric for safety.

Mythbusters also did experimenting with static and gasoline vapors https://www.youtube.com/watch?v=VjrkwxMhc4s