Everyone knows that the world's supply of oil isn't going to last forever, the question I pose is what do you think will replace the gasoline engine?
My opinion is that the most economical (in the long run) would be to remove the car from the equation completely, and replace the entire commuter netwrok with maglev vehicles sealed in vaccuum tunnels. It's a little out there, but it could save energy: Magnetic levitation in a vaccuum would be able to keep its kinetic energy infinitely (no friction to slow it down), so that all the energy required would be to accelerate the train(/individual pods?).
Its just an idea.
A magnetic thing was what I was thinking of too, although solar/electric cars are more realistic in the present time, if you want to know where the energy to plug your car into comes from, aren't they coming up with nucluer fusion?
I don't think mass maglev trains are very near.
They are quite expensive to run right now.
I think solar, wind, hydor or nuclear power will be the short solution.
We have enough uranium already mined to meet all of the current energy needs of the world for 1000 years with nuclear power. All we'd need to compensate is the growth of our energy consumption, so it doesn't get too out of hand. Also, we need to get rid of our dependency on oil - it's polluting the environment and creating a global economic rift between the rich and the poor.
Oil should be used for other things, like engine oil(Not gasoline, I mean like Penzoil) or something like that.
And I think that some other synthetic material that is better can be made.