I am really interested in learning more about the pitfalls of running E85 in a Pentastar. I recently built an engine for my CJ-7 designed to run E-85; 418 cubic inches, 11.5:1 compression, port fuel injection, stainless and Teflon fuel system. It seems like a natural for the 11.2:1 Pentastar and I was planning to get a Livernois tune and run E85. Specifically, I won't be running either of these Jeeps as flex fuel vehicles. It will be straight E85.I wasn't talking about engines designed to run it. I was talking about guys who tune their engines for E85 and they are NOT flex fuel engines.
Kevin the Pentastar designer flat out said it would shorten the life of the Pentastar and the context was not a flex fuel engine. I didn't ask him about the flex fuel version because I don't have one. In fact, I didn't ask him about E85 at all. He brought it up as something he would not do to his Pentastar. I'm assuming there there must be people who put it in non-flex fuel engines. So the distinction is that the engine has to be designed for it. But Kevin (the engineer) also said he still wouldn't run it his own Pentastar, even if a flex fuel model. I'll ask him for more detail about why, but he referenced it stripping oil from cylinder walls and being hard on oil.