[chuckm]

AMEN!

If there were a ton of easily recovered energy in exhaust gas, then two things would become quite apparent: 1) The engine was not doing a good job and 2) Auto companies, with the hoards of engineers working full time, would have pursued and knocked this out already. Heat energy, with the working medium at ambient (or very nearly ambient) pressure, is very difficult to extract efficiently without a ton of accessory equipment (power plants have feedwater heaters, extremely high pressure pumps, and lots of etc). All of this means extra weight. If BMW is pulls off the system the system evolutionmovment mentioned, it would be a hell of an engineering accomplishment.