i put a reaction chamber on my 91 gmc sierra and went from 12mpg to 15mpg and smoothed idle say what you want but it worked for me and i honestly don't care what proof you might show me that says otherwise i saw it first hand so leave it at that, and the gmc wouldn't get better FE no matter what i did driving wise before that i kept track!!!(i really don't want to get into a "GIVE ME PROOF" fight cause i don't have any to give other then what i witnessed ok)
Check this out for cryogenic processing.
http://www.cryoplus.com/pdf/icwptct.pdf
and this chart on ICE fuel losses
http://www.fueleconomy.gov/feg/atv.shtml