My manual said the same thing.(Johnson/Bombardier).
But for sake of a few cents a litre, I took the dealers advice and never found myself drifting around the bay with fuel issues.
Then again ,I never came across anyone who had issues.

 

Nor have I, and that's a key point. The world is full of nervous nellies who can think only of perfect-storm worst-case scenarios.

Despite urging to the contrary, my neighbour leaves a lawnmower gas can open to the atmosphere at all times and quite often sitting out in the elements. That's the type of person who then moans when the thing won't start next spring.

The dealers see a flood of them year after year and base their ethanol-is-satan recommendations on such neglectful individuals, not 'normal' people like us.