Anyone got their engine set to RON93?

[Denlasoul]

I read awhile ago about people having their cars tuned to the higher Octane gas using the Mercedes Star Diagnostic tool. Has anyone here done it? Any observations? I might have my local mechanic do it for me, if it's a positive gain.

DLS

[Renn 208]

Originally posted by Denlasoul
I read awhile ago about people having their cars tuned to the higher Octane gas using the Mercedes Star Diagnostic tool. Has anyone here done it? Any observations? I might have my local mechanic do it for me, if it's a positive gain.

DLS

Nokia mentioned a while back that while he was able to set it to 93RON, he couldn't get it to stick.

You might be better off with some UD pullies...or any of speedybenz's mods

[Denlasoul]

What do you mean by "Nokia couldnt get it to stick"? I am planning on doing the underdrive pulleys, just putting it off for now.

Speedybenz mods?!?!!? Light years ahead of me. Though I like the idea of shedding pounds, and better handling. I read shedding 6 pounds is like adding 1hp to the car.

[Renn 208]

Originally posted by Denlasoul
What do you mean by "Nokia couldnt get it to stick"? I am planning on doing the underdrive pulleys, just putting it off for now.

Speedybenz mods?!?!!? Light years ahead of me. Though I like the idea of shedding pounds, and better handling. I read shedding 6 pounds is like adding 1hp to the car.

1. nokia would be the best to clarify, but my understanding was that the setting went back to 91 on its own.

2. light years? nah, Jeff's got all kinds of doable mods...and lucky you, it's the same car now!

[jnolte]

what modz does speedybenz got??

[Renn 208]

Originally posted by jnolte
what modz does speedybenz got??

use search

[speedybenz]

I had this mod performed to my 1999, C280 V6. And it stuck to the ECU for as long as I owned it. I even went back to check it about 3 months after the change and the ECU still retained the new code.

It did make the V6 engine pull better of the bottom and through the middle of the powerband but no real gain on top. However the gain in the middle was great and I will change to this setting on my current car when I get a chance.

Jeff

[kodiak]

Where are you getting 93 RON gas? And is it actually 93 RON or 93 pump gas (R+M/2) or in long from RON + MON /2?

Thanks,
~dnm

[Brabus]

Originally posted by kodiak
Where are you getting 93 RON gas? And is it actually 93 RON or 93 pump gas (R+M/2) or in long from RON + MON /2?

Thanks,
~dnm

I don't think they're talking about switching the actual gas but actually tricking the computer that you have better gas so it uses it in a more performance oriented way. I hear this lowers mileage though??

[dwang]

I believe the theory goes something like this...

The ignition is set to a certain retard for firing. Changing the setting to 93 retards the ignition even more, thus making some gains. Does this sound right???

Here are some snapshot pics of the computer screen during the change (this was for a 203 vehicle):

[dwang]

2nd screen:

[dwang]

3rd screen:

[dwang]

4th screen:

[dwang]

5th:

[dwang]

Finally last screen:

[speedybenz]

Changing to the 93 fuel setting alters the ignition timing. It advances the timing some which can help torque in the lower and middle ofthe powerband and may or may not help the top end.

I always ran 91 octane fuel in my V6 and did not have any detonation problems. But different cars will react differently. So if you make the change you need to listin for detonation or learn to read spark plugs to see detonation on the plug.

Jeff

[Denlasoul]

What would detonation sound like?

[speedybenz]

Detonation can be hard to hear, but the pinging that you hear in some engines is sort of typical. Although the pinging noise is more of preignition and not as destructive.

You you suspect detonation you can check your spark plugs. You want to look at the ceramic around the electrode for little specks of black or balls of black to purple deposits. These are indication of aluminum being blown off the piston and then deposited on your plugs.

You may also notice the water temps go up substanially, but not always.

If I were to change the ECU to the 93 fuel setting I would run cooler plugs. probably one heat range cooler.

Jeff

[Denlasoul]

How much of a difference is 92 and 93 Octane? I think my local gas station has 92, and was wondering how much of a difference there is between the two.

[speedybenz]

Difference between 93 and 92 octane? Not enough to worry about. Ther is very little difference between 91 and 93 octane.

Jeff

[kodiak]

I might have to give this one a shot. Anyone have the software to do it? Suppose I could just go with a PowerChip 93 octane and be done with it....

~dnm

[Alps]

UK has 95 RON in the garages, thats what i run my C36 on all the time!

[Deepchord]

sounds "retarded" when you mess with the stock timing..

har har har

[98c43amg]

Hello all,

I'm new to this board. Nice to meet you all.

I've been running it [RON93] for years on and off. Among many things "just not right" w/my less than perfect C43 is it has absolutely no peddle response with ignition set to "default". I have to have it set to RON93 else I want to drive the car in a lake.

When I'm not running in RON93 mode is always becuase a service tech reset my configuration and/or reset the adaptations. Otherwise it stays set.

Additionally, I understood it =retartds= the timing, not advances it. The result is much more low and mid RPM torque. Though I find it to perhaps be at the expense of high RPM torque [though that may just be unique to my less than perfect car].

Additionally, the "93" in "RON93" is the european 93 octane. That equates to US 91 octane. Thus it's actually setting the car to operate on "cheaper" gas, not better gas. It limits the amount of advancement the ignition will operate at through the RPM range [higher octane allows for more advancement]. As an example, if you run the ignition in "default" mode with Sunoco 95 octane [US], the car will advance its timing quite a bit more vs how much it would if running with that gas and ignition set to RON93.

...at least as I understand it...

[Denlasoul]

Hello and welcome!

You said having your car set to RON93 had better low and midrange torque, and that high end might be comprimised. Do you know for sure, or are you going by seat of the pants? I'm curious b/c I want a little more at the lower end, but definitely do not want to sacrifice my top end. I guess I should just go out and find out for myself.

Thanks