"Adding alcohol to gasoline dramatically increases the ambient temperature
where ice forms. Evaporating methyl alcohol creates a temperature drop of
300 degrees F. As a result, carburetor ice occurs over a wide range of
temperatures."

Extract from:
http://www.sacskyranch.com/crbice.htm

Nobody seems to have mentioned this. Alcohol is not good in aircraft engines
where there is any chance of it causing the engine to stop!

I'm not keen on having an extra reason for having to change my pants!

Hope this helps,
Peter