buddywhite

Has anyone had any experience with adding 104plus octane boost to their fuel on a C32. Pros or cons?

mdp c230k

I know that on other newer cars it is a waste of money and can damage the O2 sensor. 91 octane is optimal for all new MBs even the C32 as the ECU controls detonation and the compression of the C32 isnt that high to need any higher.

buddywhite

Thanks, thats good info. I used the 104Plus in my boat and got good results, but that was a whole different engine set up.

rgleason

Where does one get 91 octane fuel? I live in Massachusetts. Regular is 87 octane, the mid grade is 89 octane , and high test is 93 octane. Is the 93 octane actually the 91 octane (just computed differently)?

buddywhite

Here in Atlanta we have 87, 89 and 93 octane also.

mdp c230k

In California the high octane is only 91, regular 87, and plus is 89 octane. All MBs are designed to run on 91 octane because it is the highest universally available. You are not hurting by using 93 but you are not gaining either.

pocholin

That's why I want to get my ECU reprogramed to use 93, so I gain something from using it.

Jim Banville

Won't the comupter automatically adjust for 93 octane? If the computer doesn't adjust and it is set to 93, what hapens if you put in 91?

pocholin

The computer is set to use 91 octane, if you put 93 octane nothing happens, you don't gain performance.
If you put 89 or 87 you run a high risk that under heavy acceleration getting detonation.

yobusdis

That still didn't answer the ?... I'm in Fla, and we have 89 and 93 down here. Can you get the computer reprogrammed to be optimized with 93. I'm pretty sure there is no chip and that you would have to reprogram or replace the whole computer.

Oh, and 104 in my Go Cart gave it like an extra 10 mph, works great on weed wacker engines.

pakman

I think it has something to do with altitude whether you get
93 octane or 91. In Colorado - I have never seen 93 octane.
Since the higher the octane number the slower the fuel burns, it may be that at high altitudes = less 0xygen/vol = 91 octane
at 5000 feet behaves same as 93 octane at sea level.

Asad

ValueplusClass

Dealer says use 93 octane on new E320.

old560SEL

OK,

IF you are using 93 octane and your ECU is set for 91 - nothing happens

IF you are using 91, and your ECU is set for 93 - you're going to wear parts more

IF you are using 87 or 89 and your ECU is set for 91 or 93 - you're going to risk blowing an injector

IF you are attempting to use 104+ with ANYTHING - you're going to wear out parts that much faster, with minimal gains.

pocholin

Thanks for the complete explanation

mleskovar

"IF you are using 91, and your ECU is set for 93 - you're going to wear parts more IF you are using 87 or 89 and your ECU is set for 91 or 93 - you're going to risk blowing an injector"

I don't believe these are accurate statements ...but I am not an engineer. More parts wear and injectors getting 'blown' (?). I believe the only problem caused by gas octane is possible detonation if the octane is too low...piston top damage, valve damage, power loss, and overheating.
Does anyone know if the ECU will adjust for octane deficiency or just notify you?

Nektopoli

Like pocholin said. You risk detonation, detonation is the fuel/air mixture exploding before it should, the 93 octane trick reprograms the ECU and gives the car a bit more timing advance, 6 degrees over stock is what I've heard.

A friend of mine was setting the timing on a boat motor (Chevy 4.2L V6) without a timing light, while he was doing this he gave it a bit to much advance and blew a hole through the top of one of the pistons.

Also, the reason for our car being tuned for 91 octane is it just cheaper to make one engine for sale in all 50 states.

NP

Crankin

Could you give us some insight as to how the MB's are set from the factory for the US as far as the ignition settings?
We have 93 octane in FL and some have said that there is a setting in the ignition correction program that advances the timing some, allowing you to take advantage of the 93 octane.
Is the baseline setting set conservatively by MB to protect against idiots putting regular gas in, or potential bad gas quality?
Thanks

beantownrich

I've not encountered 91 octane fuel and have to use 93 instead. It is 93 octane, which is an intl. standard.

In Europe it is near impossible to find fuels with octane ratings less than 93. If I remember correctly (correct me if I'm wrong) but the only octane ratings available are 95 and 98.

jswedberg

Remember that Europe defines their octane ratings differently - RON vs CLC - (or (R+M)/2).

I believe 98 RON is more or less equivalent to 93 CLC

Lynn

That is correct. RON is 4 to 5 points higher than the equivalent (R+M)/2. The (R+M)/2 was developed by US bureaucrats for reasons known only by themselves.

93 (R+M)/2 is common east of the Rockies, and generally unavailable in the Rockies and West Coast. I don't know why that is.

lars

We can get 94 (R+M)/2 at the pumps in Western Canada. It's popular with drivers of modified and older cars.

I wanted to mention that people using octane boosters should be very careful not to get the liquid on their skin, or to wash thoroughly and quickly if they do. I won't mention any brand names, but I remember one situation during a rally where a co-driver had a can of it spill into her bucket seat during a stage. There was naturally no desire to stop and clean up, and she wound up in the nearest hospital with symptoms that included circulatory and respiratory problems. Octane boosters can be toxic, quite volatile, and can quickly cross the skin into the bloodstream.

kiwibloke

Hehe just as a matter of interest here in new zealand regular ocatane is 91 and premium is 96....

we use 96 in all our mercs....:P

josh

Crankin

Is there a MB Tech that can tell me what the US S class 2000 MY cars were set up for on gas octane? MB says to burn 91 US octane, but some areas may not have that, or if so, it may be of a poor quality. Is the baseline ignition setting for a lower octane gas as a margin of error to be conservative? Is the 93 RON ignition correction setting in the ignition program more aggressive than the baseline setting, allowing for more timing advance?
Thanks

speedybenz

I had my ECU fuel setting changed to the 93 value about 4 months ago. My car is a 1999, C280-V6. I live in California and run 91 octane gas.

The only real change I note is that the midrange and lowend torque have gone up just little. Nothing to get real excited about, but the change is there.

No real advantage on the top end.

I put in 87 octane just to see what would happen and the car was less responsive but I could not detect detonation, so the ECU must have been picking it up and adjusting the computer.

Jeff