Originally Posted by GT3 Tim
Check out PencilGeeks dyno results with 100 octane and 91 octane. He got a decent increase in power.
I don't totally agree with the last part of your post about the car being tuned for 93 and not producing more power after that. Fact is, the jury is still out on that. PencilGeek proved that octane ABOVE 91 is beneficial. The question is how much above 91....Even though he used 100 octane, it is possible that you would realize no gain in hp above 93....but it is impossible to tell at this point as we only have data for 91 and 100. You may be right in that the car is capable of advancing the timing up to what would be required for 93 octane. But without data for octane in incriments of "1" or so, we cannot be quite sure. Personally, I doubt anything much higher than 93 would be of benefit (actually, the higher the octane, the LOWER the specific energy). So anything much higher than the car can accomodate (timing) could actually result in less power than the theoretical max (93 or whatever it may be).
Anybody want to mix some fuel and toluene (accurately) to achieve octane incriments of "1", drain their tank each time, and dyno test each batch to see what's the best octane level to use? lol
93 may be the max.....but we cannot claim that it is at this point in time, unless there is data to support it. Is there data to support it that I did not see?
Yep, agreed 100%, some say its 95 octane where it is tuned other tuners that I have spoken to say its 93 but none of these were BMW tuners (they were MB tuners lol
), surely it can't be 100 IMO. But again, agree we don't yet know these things for a fact.