My US Import boat now runs so much smoother after I have taken care of all of the "E10" related issues. We do not have E10 here...
Things like Generator fuel-pump impeller dis-integration, water condensed in fuel tanks, Cool-Fuel disintegration, hose replacements, filter replacements etc.
More money, oil and parts (parts costs CO2 to make) has been spent on overhauling those issues than the E10 ever saved the environment.
Put you cars on Natural Gas and so the boats can get their lovely petrol!
I do plan to put in a Nuclear engine in my boat - once they are ready for my size. *G*