I have a question as to what US octane is preferred for our 4kq jt engines (or in that case any 2.1, 2.2 stock 5 cyl NA motors). This is a issue floating around on the quantum syncro list and since I drive both jt code cars I thought I would throw this question to this list for comments and suggestions. Any input is appreciated. btw I use 91 for what it's worth