If you mix your own E85 and say the Ethanol absorbed water from storage... say 3%.

What damage can it do to the engine?

 

Why are you storing fuel?

 

A lot of people that aren't very close to e85 store it...

 

From a chemical stand point that depends on the weather and how cold it gets before it goes through your engine. But I would think It could take sometime before the ethanol becomes effected by the water to cause any damage to your engine. But thats just my hypothesis....

 

there's info on the internet. key issue is formic acid is a byproduct of combustion when the engine is cold. why is there 3% water?

 

Keep it tightly sealed in a full container, the less air the less moisture than can be absorbed.

 

dont worry about it, its very common to run alcohol/water through a motor.. think of the 50/50 mixes people used when alcohol injection was popular.