Pretty much every gas station for every brand has 94

 

You guys are lucky out west then. We don't here.

 

Here guys in Greece we have shell too and the have the normal that it is 95 octane and the v power racing that it is 99+octane they say..from the beginning i put the 99+.What you suggest is better for my 997 4s 08 model?

 

Hey Illias, octane ratings are not calculated the same way everywhere. Here in North America, the numbers are presented as PON which means pump octane number. PON =(RON + MON)/2.

In greece, your 99 octane is probably just the RON number. MON is lower so the when both are added and divided by two, PON always gives a lower number than RON by approx 4-5 units usualy. So your 99 octane is probably 94 PON in North America...

 

Thanks for the feedback.
I have tried all three major brands, Shell, Mobil and Chevron and also from different stations with the same results; the car performs very well however and with no drivability concerns at all. I have a colleuge with an 08S and whenever we have a quick little fun race (say from 60-100 on the interstate) my car always pulls on him, so I figured perhaps my ecu was set a bit more aggressively. The knocking only lasts for a second under certain throttle rpm conditions until the knock sensors jump in and correct it. I really haven't fully pursued this issue as I read on Rennlist a few folks were having the exact same issue and none posted a fix...I agree with your comment about the SA (he's been doing this far too long and its starting to show). I only have about 6 more months on my lease so unless I have another reason to bring the car in I'll probably live with it; the greater concern is what to get next.

 

99 in Europe is equivalent I believe to 93-94 octane here in the states.

Dave

 

Here's the rennlist threads on 997S's with knocking/octane issues:

http://forums.rennlist.com/rennforum...ine-knock.html

http://forums.rennlist.com/rennforum...g-on-91-a.html

 

I once bought 100 octane at the 76 gas station at the La Paz off ramp of the 5 Freeway south. Since you live in Irvine, would be a short drive. Hope this helps!

 

are factory octane ratings for the car to run on 93? meaning are all of us in cali losing hp presuming the car is stock?

 

I must be old or something, as the C2S is plenty fast for me on 91 octane already. But I must try the 100 octane gas just once so I know what I am missing.

Thanks for the La Paz tip, I'll swing by there sometime.