i have not had any of the local E85 tested with a good hydrometer for the specific gravity, I do test it for alcohol content and see an increase of alcohol when let it sit in the plastic jugs in the car trailer over the winter.
It will go up as high as 88% after sitting long enough
My 15.0 to 1 compression S/P bracket race motor didn't seem to notice the difference between fresh E85 out of the local pump or after sitting in the jugs all winter gaining more alcohol content: confused
I do have a decent hydrometer that I use to use when I race in NHRA stock classes back when they would check the specific gravity on our race gas, maybe I should use it now on the E85 to see if it changes or not after sitting in the jugs a long time: work: