E85 or ethanol fuel damaging iron/steel manifolds.

Is it true that E85 or ethanol fuels can damage steel and cast iron exhaust manifolds? What i have heard is that E85 can make particles come loose from the steel/iron and those particles ends up damaging the turbo turbine wheel.

Hi. I do not find it very real for ethanol fuels. To me it's either all fluids or none of them. There is nothing so special about ethanol that would make it to have some special properties to that regard... I'm using E66 blend with agressive race gas and never saw anything that would make me suspicious to this matter...

It's more that Ethanol is hygroscopic and absorbs moisture from the environment. If the fuel has been sitting for a period of time the moisture content increases enough that a phase separation can occur leading to the water coming out of solution with the fuel and being deposited in places that are not good.

Ethanol causes corrosion with aluminium parts but never heard of such problem for steel and iron...

I would be surprised, and I wouldn't consider the water content in the ethanol to be a significant factor - remember, when burned a hydrocarbon fuel produces CO2 and H20 (water as steam), 1 litre/gallon of fuel will burn to produce more than 1 litre/gallon of water/steam.

Methanol can produce nitric acid, though, which may have a corrosive affect, but don't know if it's meaningful.