I fill up at a local grocery store chain; Meijer's. They are big in MI and Northern IL area with their own pumps. None of their pumps list the BIO content on their pumps which means that it is under B5, to me. I will also use Sam's Club in my area since this too does not state the Bio content of the diesel fuel. But what is funny is the local Walmart, 2 miles away states their diesel pumps can contain up to B20 fuel.
I refuse to fill up at BP, Mobil and Shell in my area. All of their diesel fuel pumps state that the fuel content could be between B10 and B20, along with the diesel fuel is not refined by their companies and is locally supplied. But they charge higher fuel prices for the diesel product than Sam's, Walmart and Meijers as much as $0.10 to $0.20 a gallon more.