If that's the case, then you are. Car manufacturers specify what fluids to use in your car, and even if it's the tiniest print on the back page, it still counts and shifts liability to you if you don't follow their instructions.
As for standard fuel, or E10 I guess you could call it, I have yet to see any evidence of that amount of Ethanol causing erosion.
thee is nothing you can do.. how can you prove this... and if you did they would say the motor oil or the ante freeze or some greese is causing this or the toxic air you breath.
the gas station,...supplier... he brought the contaminated fuel to the station, and the owner, probably new nothing about it until the customers started to complain about there tank rotten on the ground, sue the supplier!!!