I have only run Amoco Gold 93 octane, supposed to be the best,
I did find a Sunoco that has 260GT which is 100 octane unleaded (I mentioned it in thread called "the most beautiful thing I have ever seen")
but unfortunately his pump is broken bad, his money is tight and it may be a minute before he gets repaired, when he does I will mix 2 gallons of 100 octane on top of my 93........every tank
I could feel how rough my brand new (315 miles) engine even idled with the diablo 93 tune on, it was noisier mechanically if that's possible! it felt like crap, ran like a scalded dog, but I couldn't drive it that rough all the time
hopefully I can get Mike to email me back and find out just what I can and cant adjust, the instruction manual isn't good in my opinion, for one, the tire adjustments require choosing apply or cancel and key cycling, not just the red x or green check like the instruction have for every other parameter, I wish it was more clear..........maybe I am just doing it wrong