Hi Andman, first that article was from 1979. Meaning that todays E.F.I. systems allow and control the I.C.E. to run at optimal performance levels without detonation. Basic E.F.I. system out perform any Analog carburetor unit from those days for sure.
In high static compression engines, which is different from dynamic compression ratios (incorporating actual ratios from atmospheric conditions, elevation etc.) detonation was more prominent before E.F.I. systems were introduced. Whereby reducing ignition timing was necessary or utilizing high octane fuels to compensate. Water injection on naturally aspirated, high compression (11:1 or better in an I.C.E), especially at sea level, could benefit, again primarily in power, by keeping timing advance on loweroctane fuel. This was utilized on drag strips all over the country. Cars in the day utilizing water injection in Bakersfield didn't racing in Denver.
Also understanding the basics to the thermal dynamic transfer of heat energy and heat absorbed by the water in an Isochoric (constant volume as in I.C.E.) or as in Isobaric (higher compression like diesels) efficiencies drop unless the volumetric efficiency of the chamber is brought up by external influences. The details to all of this has been written in volumes from many bonified research institutes and from credible private sector sources for many years now. Again the source of the information is critical before accepting it's content.
Second, as I said above, unless there is credible referencing to the story ie: well defined testing methods, third party referencing to the testing and methodology, it resides in the phenomenon of pseudoscience. Which in most cases is having only some of the information.
This is a big issue amongst scientist and engineers. Here you can understand it's cause and effect from the experience of others. There are many well thought out comments here:
CR4 - Thread: Curbing the Spread of Pseudoscience
Also the fact that he claims 20-25% gains in mileage, and that would depend on the methodology in how he made that determination, could be attributed to many, many other factors, especially with that type of induction, timing and ignition system. Just my thoughts. This thread posted here in Ecomodder alone provides some good suggestions for testing mileage:
http://ecomodder.com/forum/showthrea...ery-11445.html