Most of what I have seen for sale is B20, or 20% biodiesel, 80% petroleum diesel. There is also B100 (100% biodiesel) for sale some places, but I’ve never seen it. I don’t know if they change the blend in the winter time like they do with ethanol. E85 is 85% ethanol, except that in the winter time they make a “winter blend” that is a good bit less than 85% ethanol because really high concentrations of ethanol in in your fuel makes it hard for you to start your engine in the winter time. Biodiesel will gel when it gets too cold.
From what I have heard, the farther north you go the lower the blend. I don’t think it is changed even in the summer. Down here, B80 is good enough for winter. I don’t know of anything running B100 except for maybe a few peaking generators.