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

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.