What is oil commonly referred to?

I remember that from The Beverly Hillbillies theme song "black gold, Texas tea..."

What a different world it will be when its gone!

Aradlaw, Exactly what I was going to say. Was only a young kid when it was on UK TV but remember the opening song saying "Black Gold" & "Texas Tea"

Goodboy, perhaps... if oil (or a synthetic variant) isn't around you can say goodbye to commercial air travel as well as many other things. For the time being it's a necessary evil.

I'm going to start calling it liquid licorice, that's just plain funny.