Thanks Shoestring for the link to the additives, one part of which forecast impending doom for all planes or kit-cars that have alloy tanks... quote....
'Ethanol is also corrosive to other metallic components including zinc, brass, lead and aluminium which will degrade over time under prolonged exposure to ethanol.'
btw, nobody seems to suffer much from 'Plug Wiskering' now, it was often found in the days of 5 Star fuel (101+ octane).