What about water in the gasoline?
M wrote:
Anyone has done the test of dropping the alka seltzer into mogas known
to have ethanol? Did it fizz?

I can definitely say that alka-seltzer does not fizz in ethanol free
regular gasoline. Just tested it today and Jay did that a few days
ago. Now I end up with this pack of alka-seltzer that I need to know
if I should keep it in my fly-bag!