They had more than a century to get it to the current level of efficiency, but "down the road" will be less than a decade from now. Talk to Elon Musk about this, and you'll be talking to a true visionary, who is able to make things happen too. Although, I believe his Tesla configuration is not going to be the dominant propulsion method for a long time either, because others have superior systems in the works already as well. Renewable energy is the most desirable way to go for a secure future. Fuel cells, compressed air, hydrogen, etc, etc. Elio could be the crutch we need with which to wait it out.Maybe down the road, but in the mean time I have faith (a belief) in the efficient gas engine being here for a while. There is plenty of gas and after that plenty more natural gas. Go Elio. Amen (oops, So Be It)