That's a good point, I believe the Hemi was designed around 89 octane, how many people actually run that? I used to when I towed, but I tow so often that I was spending a fortune on migrade now that's it's $1 a gallon more than regular, so I went back to regular.
They are. I had a Jeep w/the hemi. I can feel it being a little sluggish when I put 87 octane in it. 93 made a difference but it is a little spendy. 89 was the happy medium