The Zama diaphragm has been sitting in E85 for 24hrs with no deterioration or swelling. If I rub it hard it still feels ok, no black comes off or anything and it still has it's nice shape. I had to top off the E85 about half way through and then cap it because some of the fuel evaporated. So maybe it sat in E80? I don't think I have to worry about my leaf blower now.