I reliize owners manual recommends 89. I have tried both and did not see any difference in performance or millage. I have installed the trailer hitch package avalable from Chrysler ( when you take the receiver out, you can't tell it has a hitch) and have towed a car trailer with no problems. Every one I know it this area all use the 87 octane gas in their 5.7s. The 37 Dodge was my first car, and I have had several other new Chrysler products I wish I had kept. I will try to post pictures later.