Not necessarily. Could have been e82, e80, e78, e75 etc. Pump could be off from e10 also. Could be higher. I have seen over e10 at the pump near me.

Youre right. Probably an OK reading considering E85 is usually less.

In our area the E85 gas pumps say "contains 70-75% ethanol" ( or close to that ) They lower the alcohol content for winter so I wonder if I got the E85 winter mix.
The GM flex fuel sensor should be pretty accurate .. I hope!!

What did you do in terms of the tanks for winter storage being you had a decent alcohol content in them?

I`m on E in both tanks after that run , but I also added Marvel mystery oil and Amsoil Ethanol treatment at the launch before taking it out for the season.
I have a few bottles filled with 33% ethanol.
One is open to atmosphere
One is closed.
One is treated with the Amsoil
One is treated with the another ethanol stabilizer available locally.
They`ve been sitting around for a few months .. it`ll be interesting what happenes 6 months from now.

nice test to do ! curious to see the end results !

Thats what i always do -Burn that chit up and start fresh in the spring.

Good work man.

I have been running e85 for around 15 years now. I never had an issue, except last year. I always run alcohol lube in the fuel, except this time. I didn't add any to the tank and had my car down longer than I planned. It was suppose to be a few weeks and turned into 4 months. Some of the injectors wouldn't open. Previous to this, I had the engine not run for months at a time, probably 4 or more months. Never an issue. I was able to get them unstuck luckily.

Honestly, for the money you have invested, I would remove the injectors and pickle them for the winter. If mine car will be down for extended time, I have started doing this.

I bought a fuel injector flow/ test machine. It was cheap, and it's nice to see the flow on the injectors, and you can flush all the e85 out. When your done cycle the injectors with some light weight oil.

I have pulled the injectors out of every car in my family and cleaned and flowed them all. I even pulled the 2 tiny injectors out of my 20hp outboard and flowed and pickled them for the season. After I made 2 adapters for them because they were so small.

Interesting .. you run pure E85 thou.
What alcohol lube are you running ?
Marvel has some good lubricity

where did you get the injector testor/cleaner