Originally Posted by DIGItonium

K thanks! My coworker has a Mazdaspeed6, and she complains about engine knocking. She's under the impression that all the gas stations here have 10% ethanol blend regardless of grade, and they don't even have to put a sticker to tell the customer. Last year I saw stickers all over the place about ethanol blend being required. That makes me a bit worried. I did some brief research, but got more confused. I wouldn't want to get a nicely tuned FI setup, and then blow the engine down the road due to craptastic fuel blend.