I saw a few posts on different net sites concerning various problems with a number of different vehicles regarding the use of a 10% ethanol blend. These problems involved a number of concerns including, rubber seals deteriorating causing fires/leaks, gumming and a number of other problems I don't recall. I live in the midwest and the 10% blend is widely available and will give you a 90 octane rating........1 shy of the required 91 octane. I will probably just use premium, BUT if the 10% blend is cheaper AND does NOT cause ANY problems, I might lean in that direction. What do you think? BTW, my car is to be a 2.5 with automatic if that makes any difference in your reply. Thanks for your time and consideration!