Hi Jurek -

I'm an engineer as well, and your point regarding the avaiability of more oil is totally correct - at $200, we can probably develop the chemistry to make it from oxygen, hydrogen and carbon.

Substitutabillity will hinge on cost.

This applies to fuel sources, as well as fuel use (hybrids) and transportation pattern modifications.

What I doubt is that there will be a game-changing discovery which will significantly drop the cost of transportation fuel.

Supply and demand will dictate the price, while new sources or technologies will come on stream as the price justifies it.

Briefly, I don't worry about a fall in the price of oil, but expect that the optimistic predictions ($200/barrel) will be moderated by the above factors.