Ok so they aren’t really secret. You can go to the library and check them out like I did. But they do contain information about ethanol fuel that is not commonly available at present time . Since these reports are public domain I make them available to you in total along with this essay.
One report is from the US Geological Survey published in 1909 Titled Bulletins 389-394. The title of the report # 392 is COMMERCIAL DEDUCTIONS FROM COMPARISONS OF GASOLINE AND ALCOHOL TESTS ON INTERNAL COMBUSTION ENGINES. By Robert M. Strong. This report can be found on the internet Full report at https://pubs.usgs.gov/bul/0392/report.pdf
This report is a summary of the commercial results of 2000 tests done by the USGS in 1907 and 1908. “The tests dealt primarily with gasoline, forming part of the investigation of mineral fuels provided for by acts of Congress. To determine the relative economy and efficiency of gasoline it was compared with denatured alcohol” (Ethanol )….. “and to prove that the minimum fuel consumption rate for each could be obtained in approximately the same manner.”
My summary of the test results is as follows.
Ethanol can be used in any engine designed to use gasoline and will have more power but will use more fuel.
Ethanol used in an engine designed to use ethanol will get the same fuel economy as gasoline in an engine designed for gasoline in the year 1909. Because there were no fuel robbing anti-pollution devices on the gasoline engines of that time and because none are needed on modern ethanol engines we can extrapolate that a modern dedicated ethanol vehicle would get much better fuel economy than a modern gasoline powered vehicle. Maybe as much as twice as much.
The down side is that dedicated ethanol engines cannot be made to run on gasoline.
Some of the tests involved mixtures of ethanol and gasoline and concluded, “ there is no advantage in using gasoline and ethanol together. ….. Moreover, the use of gasoline in any appreciable quantity does away with many of the advantages that are obtained from the use of alcohol alone, such as safety and absence of disagreeable odors.”
The other report is titled The use of Alcohol and Gasoline in Farm Engines It is from the US Dept of Agriculture 1909. Farmers bulletin No. 277. By Charles Edward Lucke.