From what I read and understand is that the recommended fuel is high octane 91 or better. I think the manual says of you put regular gas then just put premium on next fill up. It wont hurt your engine but performance might be lacking.
I have a 2003 G35 and have used mainly regular. I have had no problems. If I would hear engine knock, I would move to the next higher grade. I really not have had that problem. As stated, the performance may be less, as I believe that the the spark is made to come later to eliminate engine knock (by retarding the spark, performance is lessen in general), however, in everyday driving, I have not noticed this.
Type of gas for Infiniti Q40
Linear Mode
