You see, again this whole conversation is off topic hence my frustration. First of all I haven't tuned my car, it was tuned for me as stated in my OP when I refer to "my tuner". I am aware of issues that might arise from extreme temperatures, addressed this with my tuner, he mentioned exactly what you are talking about and basically told me that this is a non-issue. The car was tuned very conservatively, is being logged all the time and runs great. Can we finally put the temperature issue behind us please.
Going back to my OP I have asked very simple, very specific question about FUEL. You were the one who went off on assumptions ...did you even read my OP? Stop putting words in my mouth, read OP and trust me I will be very humble. After all this we are back to square one.
I agree that octane rating should be a good enough warrant not to even have this discussion but CALI gas has rating of 91 and supposedly is much worse to tune and has worse power gains compared to other 91 ???At least that's what I gathered from all the tuning threads. The fact is, chemical composition, vapor pressure, O2 content is different for winter gas. I think we all experience little bit lower milage on winter gas. It might be due to higher O2 concentration per volume of air in cold weather in which case tune would add fuel to compensate. Theory #2 - maybe winter gas is in fact more oxyganated hence ecu needs to run little bit richer mixture? I don't know, that's why I am here and that's what this whole thread is all about. Maybe octane rating falls within some tolerance and is a non issue on 99% of the cars but could be an issue on tightly tuned turbocharged cars. Maybe that's why Subaru map is so pathetic to compensate for all that. So who again has simplistic and narrow view of the issue. You think Octane rating is all there is and I am showing some article suggesting otherwise and I am the one who has simplistic and narrow view of the problem? It's hard to stay humble when someone fails so dramatically to comprehend basic logic and tells you that you are the one that is narrow minded, don't you think?
Last but not least I am sorry for raising this question in November. I shouldn't be so narrow minded. I should make a note to ask this question in he spring so it's more relevant. You are right, talking about differences in summer/winter fuel and how it affects tune should be restricted to spring time only.
Last edited by Drogos; 11-15-2012 at 03:55 PM..