100 octane for stock E63??
So my question is this: Does the 11.3:1c.r. of a bone stock E63 warrant the use of 100 octane fuel in order to make a bit more power or is it a waste?
Thanx..
-m
-m
The E55 runs pretty pig rich as it is. By adding octane, you are FORCING the ECU to compensate what little timing it can. Be sure to do an ECU reset when you test it. Also, try it on an almost empty car. I promise you will practically feel it coming through the veins.
Edit: Absolutely, an ECU tune + 100Octane is the daddy, but then you can't run 91.
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So my question is this: Does the 11.3:1c.r. of a bone stock E63 warrant the use of 100 octane fuel in order to make a bit more power or is it a waste?
Thanx..
Like the champ needs 100 0ctane , LOL whooooosh
The E55 runs pretty pig rich as it is. By adding octane, you are FORCING the ECU to compensate what little timing it can. Be sure to do an ECU reset when you test it. Also, try it on an almost empty car. I promise you will practically feel it coming through the veins.
Edit: Absolutely, an ECU tune + 100Octane is the daddy, but then you can't run 91.
I've dyno'd and run at the strip with 100 octane in the tank, giving plenty of time to adapt. The ECU was never tuned for 100 octane and unlike other boosted applications AMG did not leave the tuning open-ended to allow it to take advantage of extra octane. You know that you can't rely on a butt-dyno for this kind of thing.
I don't understand how you are correlating A/F ratio with added timing. The ECU isn't forced into anything, you can run a 93 timing/fuel map with 100 octane, it just won't run that well. In my testing I have seen that instead of leaving timing maps somewhat open ended, they have a ceiling. That prevents the ECU from taking advantage of the extra octane, and will actually theoretically hurt performance because without that extra timing - you are going to lose power with higher octane. Higher octane is harder to burn, so without the room to compensate for that characteristic, it will negatively impact performance.
Your car may run better on 100 than 91, that I cannot really speak about, but my car ran worse (startup and throttle response) on 100 than it does on good 93. You guys have some really, really ****ty fuel in CA so it may not just be the octane rating itself of 100 that helps, but also the actual chemical composition of the fuel that helps your car run better.
The moral of the story is, 91 octane is the anti-Christ.
-m
The fuel filler door on the E63 says 91 octane,in N.Y. here we have 93octane&a few Sunoco's have the 94Ultra.
I guess I will just stick to the pump gas.I have a 55g drum of C12,along with 6 or 7 5gallon pails of MRX01,U4&MR9 that I run in the bikes but they are all leaded so I can't even mix a bit in the tank.
I'll just take the spare out&all the extra weight&see where that puts me at the track
The fuel filler door on the E63 says 91 octane,in N.Y. here we have 93octane&a few Sunoco's have the 94Ultra.
I guess I will just stick to the pump gas.I have a 55g drum of C12,along with 6 or 7 5gallon pails of MRX01,U4&MR9 that I run in the bikes but they are all leaded so I can't even mix a bit in the tank.
I'll just take the spare out&all the extra weight&see where that puts me at the track

Custom mapped ECU + Race Fuel = Not a waste
The fuel filler door on the E63 says 91 octane,in N.Y. here we have 93octane&a few Sunoco's have the 94Ultra.
I guess I will just stick to the pump gas.I have a 55g drum of C12,along with 6 or 7 5gallon pails of MRX01,U4&MR9 that I run in the bikes but they are all leaded so I can't even mix a bit in the tank.
I'll just take the spare out&all the extra weight&see where that puts me at the track


Can you please double check and let me know? I'd be interesting if some cars are tuned for 91 and others for 93
http://www.mbusa.com/models/features...E63&class=08_E
http://www.mbusa.com/models/features...E63&class=08_E
I went to my local mercedes dealer and I opened the fuel tank door of over 10 non-amg models, and found that it said minimum 91. I also checked at least 4 AMG models (all 2007+ 63 engines) and saw minimum 93.
My car, juicee's car, rarfinancial, etc... all say 93. That's why I was surprised when you said 91
I've dyno'd and run at the strip with 100 octane in the tank, giving plenty of time to adapt. The ECU was never tuned for 100 octane and unlike other boosted applications AMG did not leave the tuning open-ended to allow it to take advantage of extra octane. You know that you can't rely on a butt-dyno for this kind of thing.
I don't understand how you are correlating A/F ratio with added timing. The ECU isn't forced into anything, you can run a 93 timing/fuel map with 100 octane, it just won't run that well. In my testing I have seen that instead of leaving timing maps somewhat open ended, they have a ceiling. That prevents the ECU from taking advantage of the extra octane, and will actually theoretically hurt performance because without that extra timing - you are going to lose power with higher octane. Higher octane is harder to burn, so without the room to compensate for that characteristic, it will negatively impact performance.
Your car may run better on 100 than 91, that I cannot really speak about, but my car ran worse (startup and throttle response) on 100 than it does on good 93. You guys have some really, really ****ty fuel in CA so it may not just be the octane rating itself of 100 that helps, but also the actual chemical composition of the fuel that helps your car run better.
The moral of the story is, 91 octane is the anti-Christ.
-m
Keep in mind that we only have 91 octane in Cali. So, if I run 91 octane and then put in 100, I may see gains IF the ECU compensates at all. That is where my point about the higher octain causing advanced timing. I do not know where you got your info from, but adjusting (although minor) for varying fuel octane / quality by advancing or retarding the timing is exactly one of the functions of the ECU.
Do me a favor. You said you dyno'd with and without, etc. Post your A/Fs and see what the difference is. IF the dyno runs both show similar A/Fs, then that is some indication that the ECU IS INDEED adjusting for the more volatile fuel. The ONLY way to modulate is by timing.
I've dyno'd and run at the strip with 100 octane in the tank, giving plenty of time to adapt. The ECU was never tuned for 100 octane and unlike other boosted applications AMG did not leave the tuning open-ended to allow it to take advantage of extra octane. You know that you can't rely on a butt-dyno for this kind of thing.
I do not know where you got your info, but ALL ECUs have some range in each parameter. Nothing is set in stone. I never said the car was tuned for 100 octane. I even said a tune (advance timing by 6 degrees) plus racing fuel would really do well. I just said that 100 octane runs BETTER than any regular pump gas available in San Diego (91 octane at best).
Do me a favor. Post the dynos, especially the A/F ratios. IF the A/F ratios are similar then that is an indication that the car is ADAPTING. IF it goes fat as crap, then you know that you have gone past where the ECU can compensate and it is dumping fuel to protect from a POP!!
I don't understand how you are correlating A/F ratio with added timing. The ECU isn't forced into anything, you can run a 93 timing/fuel map with 100 octane, it just won't run that well. In my testing I have seen that instead of leaving timing maps somewhat open ended, they have a ceiling. That prevents the ECU from taking advantage of the extra octane, and will actually theoretically hurt performance because without that extra timing - you are going to lose power with higher octane. Higher octane is harder to burn, so without the room to compensate for that characteristic, it will negatively impact performance.
See above. I am saying that the added octane will cause the ECU to advance the timing to a point. After that, it becomes diminishin or even detrimental returns.
Your car may run better on 100 than 91, that I cannot really speak about, but my car ran worse (startup and throttle response) on 100 than it does on good 93. You guys have some really, really ****ty fuel in CA so it may not just be the octane rating itself of 100 that helps, but also the actual chemical composition of the fuel that helps your car run better.
Agreed!
The moral of the story is, 91 octane is the anti-Christ.
-m
I went to my local mercedes dealer and I opened the fuel tank door of over 10 non-amg models, and found that it said minimum 91. I also checked at least 4 AMG models (all 2007+ 63 engines) and saw minimum 93.
My car, juicee's car, rarfinancial, etc... all say 93. That's why I was surprised when you said 91

Just be careful the Sunoco is not leaded,as most of their race fuels are
Again the trick is in the mix, do your homework
thats the fun of it.
Again the trick is in the mix, do your homework
thats the fun of it.Oh crap, where is a VP dealer near Fontana?
The fuel filler door on the E63 says 91 octane,in N.Y. here we have 93octane&a few Sunoco's have the 94Ultra.
I guess I will just stick to the pump gas.I have a 55g drum of C12,along with 6 or 7 5gallon pails of MRX01,U4&MR9 that I run in the bikes but they are all leaded so I can't even mix a bit in the tank.
I'll just take the spare out&all the extra weight&see where that puts me at the track

How is it that your fuel door says 91 octane where 93 is available and mine says 93 where only 91 is avail? WTF, :-)
EDIT: Ok i read the thread LOL, all 63's say 93?
So a mix 100 plus 91 is best to achieve 93 unless you have 93 at the pump , then 93 is likely best. see what happens adding 100 to 93 , I am real interested in this as are many folks on this site
Last edited by juicee63; Nov 13, 2007 at 01:38 AM.



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