In Europe we have two choices of gas. I read somewhere that buying gas with octane nr. 98 in stead of the Super Bleifrei with octane nr. 95 would be a waste of money because the car (997.2) won't be able to exploit it.
For U.S. markets it would be the difference between 93 and 91. Any opinions on this matter?

 

Nothing less than 100 grade

 

I use 93 pump number octane for all of our cars ( MB, BMW, VW, Porsche). Shell or Exxon.

 

anything over 91 is a waste of money because i believe our cars came from the factory tuned to use 91 octane gas. i still put 93 in because it's the highest they have or the only option around here.

in north jersey, most areas are 87 / 89 / 91 or 93

 

Thats incorrect, the cars are tuned for 93 octane but will run on 91 octane as the car will pull timing for the lower quality of gas. If you open your fuel filler door it will recommend 93 octane. You live on the east coast where you can still buy 93 octane. For us here in Kalifornia I have to blend 4.5 gallons of race 101 unleaded to get me to 93 octane which I religiously do every fill up.

Dave

 

http://www.m3post.com/forums/showthread.php?t=259770

 

I always wondered about the capacity of the ECU in this regard as well. It's target is 93 octane, can adjust downward if needed (based on knock sensor behavior I presume) but can it adjust upward as well? Thus can the car take advantage of 95 or 100 octane fuel? Or is it just a waste?
For the heck of it, I once tanked up with 100 octane. Didn't notice much (or anything more likely) and it did put a big hole in my wallet. But I did feel like a much better person for doing so.
I haven't thought about mixing - being in Kalifornia as well.

 

Nope, just 93, above that it will burn hotter and you may get small gain, but the ECU will not adjust for it, it will treat it like 93. Also, I believe the 355hp specs on these cars is based on 93 octane fuel.

 

well, i'm a 996, but think the car is tuned on similar grade of fuel. i was STUPIDLY using the local 7-11 91 octane (which is citgo) gas for some time, the car seemed a bit sluggish to me.....NOW, I use the Shell 93 Octane, and the car has a bounce in it's step again.....NEVER GOING BACK TO "CONVENIENCE" SHOPPING......

 

Ya habibi, 7-11 gas is like cheap camel food. I wish I had the 104+ octane here that we have in Q8. lol although they need it there with the temps well above 120 degrees for several months of the year.

 

Do you only fill where race gas is available? A rare sight in most areas.

 

91 Shell. I never get Costco gas.

 

Unfortunately yes...I am lucky though near my home in Playa del Rey there are 3 gas stations within 7 miles (one just 1.5 mi. away) that sell racing unleaded. I was getting F&L 105 Unleaded and I would blend 3 gallons of it with 13 gallons of 91. Now all I can get is 101 F&L or VP Racing 100.

If I am in a pinch I will run Torco Unleaded Race Fuel Concentrate. Its not an octane boost but an actual race gas concentrate.


Dave

 

whoops my mistake! you're right. good thing i haven't put 91 in yet! guess i won't! the z4 takes 91 tho.

 

The 76 Station on Woodside Road sells Sunoco 100 race gas.