Octane setting at base and loving it
Thread Starter
Senior Member
Joined: Sep 2005
Posts: 411
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2003 E55 K1
Octane setting at base and loving it
Well I've gone full circle, or have I?
I changed octane setting to 93 last week and didn't notice much change. Was told by master Yoda (VRUS) that I had screwed up and "base setting was best." This was confirmed by a different MB service rep. So today I changed to Base setting. (Notice I didn't say back to Base setting!!)
After driving for a 100 miles or so, I can now say that car is much stronger than it was before or after change to 93!! In fact, car is as strong as it ever was, even before ECU reflash! I cannot floor the car at any time in first gear without losing all traction. I can't even floor car in second gear at 25 or so if it downshifts to first because car again loses traction. And this with ESP on!Before change to 93, I could hardly break tires lose from a roll.
I'm wondering if ECU reflash changed octane setting to something other than Base, and by going to 93 then to Base I got it back to where it should have been all along. Does this make any sense? How else do you explain improvement in performance??
I changed octane setting to 93 last week and didn't notice much change. Was told by master Yoda (VRUS) that I had screwed up and "base setting was best." This was confirmed by a different MB service rep. So today I changed to Base setting. (Notice I didn't say back to Base setting!!)
After driving for a 100 miles or so, I can now say that car is much stronger than it was before or after change to 93!! In fact, car is as strong as it ever was, even before ECU reflash! I cannot floor the car at any time in first gear without losing all traction. I can't even floor car in second gear at 25 or so if it downshifts to first because car again loses traction. And this with ESP on!Before change to 93, I could hardly break tires lose from a roll.
I'm wondering if ECU reflash changed octane setting to something other than Base, and by going to 93 then to Base I got it back to where it should have been all along. Does this make any sense? How else do you explain improvement in performance??
Out Of Control!!
Joined: Sep 2004
Posts: 13,394
Likes: 6
From: San Diego
2015 S212
Well I've gone full circle, or have I?
I changed octane setting to 93 last week and didn't notice much change. Was told by master Yoda (VRUS) that I had screwed up and "base setting was best." This was confirmed by a different MB service rep. So today I changed to Base setting. (Notice I didn't say back to Base setting!!)
After driving for a 100 miles or so, I can now say that car is much stronger than it was before or after change to 93!! In fact, car is as strong as it ever was, even before ECU reflash! I cannot floor the car at any time in first gear without losing all traction. I can't even floor car in second gear at 25 or so if it downshifts to first because car again loses traction. And this with ESP on!Before change to 93, I could hardly break tires lose from a roll.
I'm wondering if ECU reflash changed octane setting to something other than Base, and by going to 93 then to Base I got it back to where it should have been all along. Does this make any sense? How else do you explain improvement in performance??
I changed octane setting to 93 last week and didn't notice much change. Was told by master Yoda (VRUS) that I had screwed up and "base setting was best." This was confirmed by a different MB service rep. So today I changed to Base setting. (Notice I didn't say back to Base setting!!)
After driving for a 100 miles or so, I can now say that car is much stronger than it was before or after change to 93!! In fact, car is as strong as it ever was, even before ECU reflash! I cannot floor the car at any time in first gear without losing all traction. I can't even floor car in second gear at 25 or so if it downshifts to first because car again loses traction. And this with ESP on!Before change to 93, I could hardly break tires lose from a roll.
I'm wondering if ECU reflash changed octane setting to something other than Base, and by going to 93 then to Base I got it back to where it should have been all along. Does this make any sense? How else do you explain improvement in performance??
Are you sure you were at "base" in the beginning? What is base called on STAR? I had heard that MB was having complaints of pinging in their higher compression engines and were considering retarding timing. I do not know if this was done or not or how. Mine will be in on Thursday, so I'll see about it as well.
Member
Joined: Apr 2006
Posts: 123
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E55
Are you sure you were at "base" in the beginning? What is base called on STAR? I had heard that MB was having complaints of pinging in their higher compression engines and were considering retarding timing. I do not know if this was done or not or how. Mine will be in on Thursday, so I'll see about it as well.
Junior Member
Joined: May 2003
Posts: 63
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From: Chicago area (Plainfield)
2004 E55 White
Well, how about some factual data. I had my E55 switched to the 93-octane setting soon after getting my car. When I ran it at the track it always seemed a little slow, toward the bottom end of the E55 performance curve. I had the car out several weeks ago at ChicagoX’s little meet. I ran a 12:78 12:72 and a 12:61 at 108 to 109 MPH. ChicagoX ran about the same times but then ran a 12:41 later in the day. That got me thinking about the 93-octane setting and what VRUS said about it. So I took my car into the dealer and had them set it back to “base” setting. By the way, the tech said it is now policy to get ok’s on any ECU changes from higher up in order to stop tuner changes. Sunday I went to the same track (US41) that I ran at before to see if there was any change. Surprisingly ChicagoX was there also. It was very crowded and I only managed one run, but what a run! 12:25 @ 113 MPH and ChicagoX ran 12:30 @ 113 MPH right after me. I am very happy and VRUS is master YODA. VRUS, thank you, thank you, thank you for the good advice. No, how about the ASP pulleys?
Junior Member
Joined: May 2003
Posts: 63
Likes: 0
From: Chicago area (Plainfield)
2004 E55 White
The temperature was 83 a few weeks ago and about 80 for the Sunday runs. There was less humidity, so I think the conditions were better, but the increase in performance was considerable. I can really feel the difference in 1st and 2nd since the octane change. I also have a 2003 mustang cobra that has a blower on it and increased timing makes big differences on them also. I may have to modify the mustang some more, my daily driver 4 door is almost as fast now.
