This is why i was concerned with putting in 92 where the manual calls for 91. I did try putting 89 in it because i WAS concerned with putting higher octane than called for, and at least havent seen any difference power or behavior wise yet, but ive only ran about a quarter of a tank of it so far. Should I just say fuck it and go back to 87? Ive ran 87 for 6 years in it and the car has never been anything but smooth, I was just wanting to learn about this in case it would actually give me better mileage or performance.