Eli5: Why is fuel/petroleum the liquid that makes cars run? What’s happening inside the car with this specific liquid that makes it go that can’t happen with other liquids?

Question

Eli5: Why is fuel/petroleum the liquid that makes cars run? What’s happening inside the car with this specific liquid that makes it go that can’t happen with other liquids?

In: Technology

Answer 1

You can make cars work on other liquids (ethanol for instance). But it has to do with the amount of caloric energy in the liquids, the density of the liquids, etc. Petrol/gasoline isn’t terribly dense (so it isn’t heavier/more viscous), and has a very high caloric energy value (it burns better than say, water, which has no caloric energy). It also has a relatively low combustion temp (ie, how hot something needs to be to catch on fire, hence why you can light it on fire with a spark rather than needing an already lit flame to burn it).

All of these combine to make it the BEST, but not the ONLY fuel for cars.