Coalman

Went to a new MB dealer and had octane setting changed to 93 octane and fan reset 7 degrees lower. I also asked dealer to check other settings to be sure car is where it should be.

I didn't expect a major change in performance and I didn't get it. However, mechanic did say he also reset all "adaptive" adjustments which probably means I will have to go through a bit of a learning process. If so then car is at least as stong as before changes and performance can only get better. Also confusing matters is that temperatures have been cool and dry and performance is much improved for that reason alone.

I will keep you posted.

Jakpro1

I have to say the Johnson high flow pump was working okay but many times under harder use, she would go over 100c and hang there. Then had dealer bring me down 10c pump and no joke, at the dyno, must have pulled 6 runs back to back and NEVER went over 100c once.

I think on these cars the Johnson High Flow pump should be a must when adding any type of mods. In fact, it should be standard without any mods. Really flows the crap outta that coolant through the supercharger.

Lovin mine.

vrus

Congratulations!! You just made your car SLOWER!!

I'll say this one more time ... slowly... so that everyone understands...

The 93 octane setting in STAR/DAS is in RON standard.. Not NA standard. 93 RON is LOWER than 93 NA rating. Just so you can grasp what I am saying, 98 RON is the equivalent to the 93 we have in NA.

The BASE SETTING is actually the BEST setting. Go back to the dealer and put it back to the BASE SETTING because as it sits right now your ECU is pulling timing on you.

Coalman

Since I'm in NA doesn't 93 octane mean 93 octane or 98 RON. The mechanic knew I was trying to improve performance, I would hope he wouldn't retard timing. But thanks for heads up. I will call dealer to make sure he didn;t adjust to a lower setting.

Quick E63

Thanks... I was on my way to my dealer at noon to have it done. You just saved me alot of trouble

Coalman

Damn!!! You are correct. I just spoke to another service rep at same dealer and he confirmed what you said. I can't believe I did this. Thanks for heads up. I can't believe others who have made changes to octane setting didn't realize they were screwing the car up.

Dogshine

I didn't know this either (fortunately I haven't changed mine tho) .. thanks, vrus.

Grumpy666

Either I'm misunderstanding what you've posted, or you have some confusion about your cooling system. The Johnson pump only flows coolant through the IC circuit - it has no impact on the engine's cooling system. The 10 degree reduction is for the fan turn-on temperature, not the pump.

vrus

Ahhh.. Young Jedis... Learn to trust the force you must.

jangy

DUDE, I never knew it that way. Or at least that the base setting was BEST!! Is there no mod to advance the timing a bit without getting an aftermarket ECU mod?

tigerlam92

Thanks. Learning something new because I failed to double check.

So according to wikipedia, then 91-95 octane rating in Europe is equivalent to 87 octane rating in US. If that is the case, what rating is baseline coming in at. I read here that the baseline is set already at 87 octane. I called the tech to ask more on what exactly was done and how. I think he did it right since he knows exactly what I wanted and the car felt good.


http://en.wikipedia.org/wiki/Octane_rating
Measurement methods:

The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel through a specific test engine with a variable compression ratio under controlled conditions, and comparing these results with those for mixtures of isooctane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-95 (regular) in Europe.

tigerlam92

Yup. I was hoping that the Star/Das will have a table like other ECU/PCM with degree versus MPa. So when they change the octane setting the timing will increase in the appropriate cells. More timing may not be the best in all the cells, too. So when the new octane setting is select, the table will adjust and we can see and verify the change.

Maybe and maybe not then.

Coalman

[QUOTE=tigerlam92;1765818]Thanks. Learning something new because I failed to double check.

So according to wikipedia, then 91-95 octane rating in Europe is equivalent to 87 octane rating in US. If that is the case, what rating is baseline coming in at. I read here that the baseline is set already at 87 octane. I called the tech to ask more on what exactly was done and how. I think he did it right since he knows exactly what I wanted and the car felt good.


So what are you saying? Are you saying change to 93 is higher than baseline? MB dealer and Yoda (see above) say differently. This is getting more confusing all the time. I would like to know before I swithch back to baseline.

OzE55

If only the US used SI/metric like everyone else.........sigh.

The setting in the car (German=SI/metric) is 93 RON. This is LOW grade fuel.
What VRUS is saying is that the base figure is HIGHER. So by changing it you have set the default to lower grade and the ECU may be pulling the timing under load to compensate for the 'apparent' lower grade fuel. This does ignore the possibility that with cars antiknock/detonation sensors that the ECU varies timing according to the fuel quality (within a narrow band, I suspect)

At least in Australia the minimum fuel grade specified for an E55 is 95RON and most use 98RON (eg Shell Optimax). Apparently if you run 98 0r 100 RON you can have some tuners change the ECU settings which presumably advances the timing etc.

Coalman

I don't mean to question your wisdom master Yoda, but if baseline setting is 98 RON, which is equivalent to 93 octane NA, then how is it manual reccommends at least 91 octane. Wouldn't 91 be too low?

lauer87

I'm confused, why would MB even put this option in the ECU if it hurt our cars? It just doesn't make sense to me.

Vetluver

Victor, is this the thread that the misinformation came from? https://mbworld.org/forums/showthrea...light=renntech
As I understand this doesn't even concern K cars.

As I understand what you are saying is that there is no way to bump up the timing more because it comes from the factory at it's highest setting. Sorry I'm a little dense sometimes.

OzE55

Baseline CAN'T be 98RON. That high level of fuel "quality" cannot be guaranteed throughout most of the world.
VRUS is saying its 93RON which equals 87 in USA.

SLK55R

But I will ask my tech ask well. When I did this ... he was stating it was 89-91-93 as the choices ...?

OzE55

Here's what the on-line manual says about fuel quality -


Petrol (EN 228)
Refuel using only unleaded premium grade petrol with a minimum octane number of 95 RON/85 MON conforming to European standard EN 228.

You could otherwise impair engine output or damage the engine.

You will find further information about petrol under “Technical data” in the index.



You will generally find information about the petrol grade on the filling pump. Otherwise, ask the filling station attendant.

If the recommended fuel is not available and only as a temporary measure, you may also use regular unleaded petrol, 91 RON/82.5 MON. This may reduce power and increase petrol consumption. Avoid driving at full throttle.

In some countries, the available petrol quality may not be sufficient and could cause coking around the inlet valve. In these cases, and in consultation with a Mercedes-Benz Service Centre, the petrol may be mixed with the additive sold and recommended by Mercedes-Benz (part no. A000989254510). You must observe the notes and mixing ratios given on the container.



Do not use diesel to refuel vehicles with a petrol engine. Never mix petrol with diesel. Even small amounts of diesel result in damage to the injection system. Damage caused by adding diesel is not covered by the warranty.


AMG vehicles

Refuel using only super unleaded petrol with a minimum octane number of 98 RON/88 MON conforming to European standard EN 228.

You could otherwise impair engine output or damage the engine.

You will find further information about petrol under “Technical data” in the index.



You will generally find information about the petrol grade on the filling pump. Otherwise, ask the filling station attendant.

If the recommended fuel is not available and only as a temporary measure, you may also use premium unleaded petrol, 95 RON/85 MON. This may reduce power and increase petrol consumption. You must avoid driving at full throttle.

SLK55R

None of us that are changing it to 93 are putting in lesser octane fuel ... if anything we are using much higher octane rated fuel. But if what Vrus is saying is correct ... not only is it reducing the timing but its a waste of the high octane fuel we are using.

If it is a lower setting it should not be damaging to the car. We are using high octane fuel.

Coalman

Lauer87,

You and I both used same MB dealer and one of their reps is now telling me Baseline is best, not 93 setting. He said one of his customers has several AMG cars and they have concluded baseline is best. Have you gone back to baseline? I am going back Monday to change back to baseline unless you convince me 93 setting has worked best for you.

Thanks

m52e55

heard RENN has new intercooler pump that drops the temp. by 30 ambient and pulls extra 30/30 hp/tq at crank when installed. does this seem reasonable?

sfkarp

Well, what's the finall verdict on this? I had my car switched to the 93 octane setting soon after getting it. I would like to know for sure if I need to change it back to base. VRUS, how did you find out about this? I wish I could read the Mercedes manual to get a complete understanding of this setting.

tigerlam92

Exactly. I have tested this in my camaro before. We will just be adding a factor of safety into the car. However the car may be a little slower, not much, since we are not taking advantage of the possible increase in timing we are allow when increasing the octane and delaying detonation.


-- http://www.infopages.net/renntech/fu...ings/index.htm --
On the other hand, if our Star/Das look anything like the above pic, then I don't see how any of our experience tech could not have konwn NOT to drop the RON octane setting. When they go to that screen it should already have shown what we have, and if it is at the highest then there is no reason to drop that set point. My tech clearly knew to increase the setting. I left him a message and will check back Monday.