First fill up! Octane question

[NorthVan]

Originally Posted by Sev Oh, we got petro canada 94 octane here too, but there aren't that many petro canadas out here, especialy not around my house. I just tank 91 octane at Esso. Pretty much every gas station for every brand has 94

This ad is not displayed to registered and logged-in members. Register your free account today and become a member on 6SpeedOnline!

[Sev]

Originally Posted by NorthVan997C2S

Pretty much every gas station for every brand has 94

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

[Ilias4s]

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?

[Sev]

Originally Posted by Ilias4s

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...

[500]

Originally Posted by Gpjli

As was stated above, the car should not knock on 93 octane. The solution may be as simple as trying gas from a different station. There is no guarantee you are getting what you are paying for. If the car does not run right that would be my first guess. Lousy gas. Try different brands as well as stations. I like Shell here in NY. I would not tolerate any knock. Not a good thing. As for the SA's statement, consider that when there is knock the sensors will retard timing to protect the engine and are in effect tuning for less power. Come to think of it, you might want to try a different sa as well

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.

[Dave07997S]

Originally Posted by Ilias4s

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?

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

Dave

[500]

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

[997TTurbo]

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!

[JAY-PESOS]

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?

[steph280]

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.