Steel fuel tanks are lined. Prior to ethanol, some small engine tanks (pre plastic) were steel unlined.

Prior to ethanol as an additive, the main issue for old gas in long stored bikes was loss of volatiles, creating what we called varnish or gunk. Ethanol added a whole new issue as alcohol attracts water, especially in a partial tank. Every temperature change, even a few degrees moves air in and out of a vented tank. This traps the moisture inside with the ethanol. This is the simple reason that the first recommendation for storing a bike, a boat, a snowblower, a generator is fill the tank or empty it. A full tank has no space for air exchange. Stabilizers take care of what little water or decomposition of the fuel takes place over a season or two.

As far as ethanol. I have no issue with it for vehicles driven regularly. But it pays havoc with any stored equipment. That is why ethanol free gas is readily available in most rural or farm related areas. While your turbo gets an ethanol boost, I track my mileage every tank and I have consistently got better mileage with nonethanol. On my bike, from 43 on ethanol premium to 46+ with nonethanol premium. Guess I need to add a turbo to my bike.

 

This is correct - I run a reasonably hot 95" motor with a Daytona Twin Tec ECM computer - With the DTT I have a data log I can access. I ran some tanks of No E gas and my injectors where firing at 85 - 90% - It was leaning the fuel mixture by10- 15% with the no E gas , this would mean 10-15 % less fuel = better milage. This was an un scientific test - just my normal riding and some throttle twisting.
As far as the E 85 making more power - guys will run it on very high compression engines - 14-15 :1 & they use a LOT of fuel.