Well for my last tank of gas I decided to try some 87 octane with the 87 superchips tune. Man my truck became a dog. It must have been knocking some, causing the computer to retard the timing. Got down to 1/4 tank, and filled it back up with 93 (still on 87 tune) and it flies. Just thought I would share my experience, and let some of those people that swear by 87 know that they could be missing out on a lot of power from their truck.

 

I get plenty of Hp on my 04 hemi with 87 oct fuel. I just don't get any gas mileage. but it gets worse if I use 93 oct. and it cost to much. Most of the time it's parked in the driveway and i drive one of my PT' around. I get twice the mileage with them as I do with the Hemi.

 

The only time I have ever experienced poor gas was my last stop in Kansas before heading to Denver. I filled up in Kansas with 87 and my truck was totally bogged down in Denver. I filled up with 87 in Denver and it runs strong. So I think that was just bad gas in Kansas not that it was 87. They do use oxygenated fuel here in CO but my truck still runs very strong on 87. Plus you said you have a Superchips tune which would adjust your timing necessitating the need for 91-93. I have heard the 87 tune with a Superchips dogs the truck. Read their forums about the 87 setting and the complaints But on factory setup my truck runs great with 87.

P.S. And just to clarify for those wondering why I don't follow the manual suggestion of 89...In the higher altitudes the octanes are 85, 87, 91. My truck does run great on 87.