Hi Roger:
Good sound advice from Paul & Mike,...
Alcohols have a
very strong affinity for water so its imperative that the tank be kept filled (especially in that coastal environment) to minimize condensation.
Both CIS and carbureted cars are vulnerable to both water-based corrosion and the effects of Ethanol for different reasons and the use of Stabil is highly encouraged.
As Paul said, your mileage does suffer and you might need to adjust CO in your CIS car to make sure its not lean. You should perform a proper plug cut to examine the spark plugs on the 356 since you might need a small jetting change.
Hope this helps,
(people will unfortunately, pay very dearly for the politics of Ethanol as its REALLY a poor choice for motor fuels beyond competition usage,....
)