Octane Reset via STAR. Does it really work?
Thread Starter
MBWorld Fanatic!
Joined: Jul 2006
Posts: 1,414
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From: Los Angeles, CA
2005 E55
Octane Reset via STAR. Does it really work?
Searched the forum and came out with different opinions.
From what I read, the method was to use STAR tool to reset the octane setting to have the ECU take out timing in results in horse power increase.
Some say to have it reset to "93 octane"(A EURO antiknock index- equates to approx 91 oct in US) .
While others say to have it reset to "Base setting" so the ECU can learn and adjust to the current octane gas that you are using.
Who has done this mod? Which setting did you reset to? Does it actually work?
Thanks.
From what I read, the method was to use STAR tool to reset the octane setting to have the ECU take out timing in results in horse power increase.
Some say to have it reset to "93 octane"(A EURO antiknock index- equates to approx 91 oct in US) .
While others say to have it reset to "Base setting" so the ECU can learn and adjust to the current octane gas that you are using.
Who has done this mod? Which setting did you reset to? Does it actually work?
Thanks.
Out Of Control!!
Joined: Sep 2004
Posts: 13,394
Likes: 6
From: San Diego
2015 S212
I think the prevailing winds claim that US spec cars already run the highest timing adjustable by STAR. It would be a great mod, if it were so. i'd be one of the first to jump on it as 100 octane is readily available for mixing.
Member
Joined: Apr 2006
Posts: 147
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From: Southwest Florida
'06 E55 Black/Charcoal
I just had my tech do it to my car last week and did not want to say anything until I got it dynoed. My original dyno was 402whp/469wtq and the temp was about 65 degrees out. I redynoed my car on sunday and my car made 410whp/495wtq and the temp was about 90 degrees. The car runs like a raped ape and it is still running pig rich.
Junior Member
Joined: May 2003
Posts: 63
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From: Chicago area (Plainfield)
2004 E55 White
I had my 2004 E55 changed to the 93 setting when I bought it. It always semmed slower than what I read of other E55's 12.57 @109 was my best. Then I had it set back to the base setting and turned 12.25 @ 113. Leave it at the base setting if you can get 93 octane.
Senior Member
Joined: Sep 2005
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2003 E55 K1
I'm going to do you a huge favor as was done for me. I also was confused and had dealer set to 93 octane. Car did not run as well. I was told "Base" is "best" and indeed it was not only better, but car has been much stronger than before I screwed around with octane setting. Why? I have no idea. Just as I have no idea why going from 93 to 91 (see above), unless you're buying crappy gas. Make sure car is set to base and you will get best performance.
Thread Starter
MBWorld Fanatic!
Joined: Jul 2006
Posts: 1,414
Likes: 0
From: Los Angeles, CA
2005 E55
I'm going to do you a huge favor as was done for me. I also was confused and had dealer set to 93 octane. Car did not run as well. I was told "Base" is "best" and indeed it was not only better, but car has been much stronger than before I screwed around with octane setting. Why? I have no idea. Just as I have no idea why going from 93 to 91 (see above), unless you're buying crappy gas. Make sure car is set to base and you will get best performance.
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2003 E55 K1
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Member
Joined: Jun 2006
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From: Bay Area, CA
E55
My theory is that this is a car built for European spec as like the alignment spec that we have is for Europe as well.
Therefore, I believe the base octane setting is set at optimal timing for premium gas under European standard. Then when needed, you can retard it to whatever lesser octane setting you want. I will not be surprise that the cars coming to US is set at a lower octane rating to retard timing to save their botton line.
I had my re-set to base setting.
Therefore, I believe the base octane setting is set at optimal timing for premium gas under European standard. Then when needed, you can retard it to whatever lesser octane setting you want. I will not be surprise that the cars coming to US is set at a lower octane rating to retard timing to save their botton line.
I had my re-set to base setting.
