jmiaebrown

I homer simpsoned the other day and put in regular exxon gas. While driving the car when excelerating it feels like there are air pockets or water in the line or something. Should I siphon remaining and go back with premium?

Thanks.

mbz4810

you suppose to add premium asap and DoNOT rev your car .

Vomit

Your car, just like all new cars, can run on regular gas, albeit with reduced performance and economy. When you put low octane gas in the car, the computer will retard the timing to minimize pre-detonation. What you are feeling is your car with retarded timing.

HLG600

Ran premium in the S and SL, but regular in the ML. Works fine with the 3.7 Litre V6. ML is lease car, but the others are owned, so not going to try in the V8 or the V12.

thebigsicilion

What you are feeling has nothing to do with retarded timing. It is true, the computer can do this but it is unlikely unless in the most severe situations. If the ecu determined pre detonation it would begin the retarding process and in that event performance would suffer but it wouldnt be that noticable. There would not be a miss or stuttering effect like "jmiaebrown" described.

jmiaebrown

I had filled it up with regular and have been driving it for a couple of days. I am about 1/4 empty so now I will go back with premium.

newton22

Do it now before it empties.

Yes it would be noticeable. Retarded timing would make the car feel very sluggish.

highdeserthiker

DRTYLNDY

Well guys I have been running regular gas for over a year now with no problems. I also have been running regular in my wifes Jaguar with no problems as well. To be honest I can not tell a difference either.
Johan

kenstudios

If you can't tell the difference then wait till something happens to your car and you try to get MB to repair it once they realize you were running on regular for a year. Your bill will not be regular.

Vomit

Uh, it depends on the car we are talking about. A normally aspirated car with relatively low compression (say, less than 10-to-1) will show little diff between regular and premium fuel. However, a high-compression motor, especially with forced induction, will definitely show a difference when running regular gas, and the retarded timing may evidence itself as the car feeling sluggish or rough.

FYI, the ECU is modern vehicles, especially modern high-performance vehicles, is constantly adjusting the spark timing, not just in the "most severe situations."

I had to put regular in my modded C32 once (middle of nowhere, no premium), and the car ran like someone attached a 20 foot Bayliner to the rear bumper with the engine having all of the smoothness of a 1960s Volkswagen. However, now that you have made me see the light, I realize that I must have just been imagining things.

newton22

Here is a scale for you.

1 (Senseless) -----------5 (Some sense)----------10 (Makes sense)
^ (Your post)

I have four words for you. Predetonation and permanent engine damage.

BBH

I count FIVE words.....

HLG600

LOL. It is still gasoline, and most newer automobiles are equipped to run on Regular gasoline. Now, when you go into aftermarket ECU tuning, then you must absolutely run Premium, due to the fact the car is set to only run that grade of fuel.

1phd1jd

Here in So. Cal. our premium gas is 91 octane (not 93). The owner’s manual of the 2004 S600 and 2005 911 Turbo S Cab states a minimum octane rating of 93. What does that do to the engine? Also, So. Cal. has more luxury cars than most places in the world so why would car manufactures (Porsche Ferrari, Benz,) allow cars to be sold here if they knew there would be a potential for disaster?

I feel a tremendous difference when I have the rare opportunity to drive my S600 or 996TT S with 93 octane gas. Faster acceleration and smother running sensations are prevalent.

In the past, all of my cars requiring premium gas ran noticeably better on 91 octane as opposed to 89 or 86 octane.

I have had experience with modifying muscle cars and as the compression of the engine rises (10–1 and up), 91 and 93 octane will not work as well as you would like. Under heavy loads the engine will tend to load up and restrict flow thus, delivering the sensations of engine roughness and lag under load.

newton22

Hey if google discards the word "and", I do too.

DRTYLNDY

I'm not really sure why you say my post is senseless! I was stating MY opinion. I ran my last 4 Vettes on regular including a Z06 on regular and guess what never a problem. I am not by any means suggesting anyone running regular but in MY opinion it is just fine. No need to be rude.

02S430

i did this once totally by accident, my gf was talking to me while i was at the pump and i thought 93 was the closest to me, turns out it was 87. shud have been there to hear the curses come out even tho it only lasted a week. but never again

newton22

I was stating highdeserthiker's post was senseless. Sorry for the confusion.

1phd1jd

Maybe that is what was wrong with my friends C6 Z06, regular gas.

angleadict

Ok so I let my father borrow my 2003 19,000 mile S55 today and in re-payment he did me the favor of filling up my car......
I was on my way home and decided to do a routine tunnel run, my first pass to 100mph went flawlessly, slowed down to around 50mph and decided to run again.... car downshifted with zero power, it was like driving my girlfriends c230, embarrassed to the nsx beside me, i pulled off the freeway and decided to open my data logger, and dl the last run made. HUGE amounts of timing retard, I called up my father and asked him what gas he used, "REGULAR son, you know I don't believe in all that octane mumbo jumbo" he replied.
Previous to this I never realized what a drastic difference it would make in such an application. However after an ecu reset and fuel dump and refill I am now a believer that the difference is huge. I don't recommend regular in any performance automobile. If the car was built and tuned for higher octane there is a reason, and octane controls how fast or slow your fuel detonates.

angleadict

Damn that was an old post........ Oh well.

Untertürkheim

Still good that you shared that information. There are plenty of people who ignore manufacturer requirements and put substandard fuel in their cars; I am glad that MB now voids warranties on cars run on substandard fuel so that warranty prices can now go back to a more normal level.

my06clk

Here's the truth about fuel....

Anybody who thinks their car won run on Non-premuim fuel is mistaken. The sam goes for those who claim "Potential engine damage" PLEASE!! IF you look at your manuals the actual "reccommend" Octane can't even be purchased in the US. so that's a joke..

And what about Venezuela, mexico, Germany, and many other countries I've visited recently and notice they too have quite a variation of fuel flavers to choose from.. IT's the same car no?

On the other hand,, and this is going to sound really hypocritical so read carefully, IF your car states that you NEED to use premium gas as Mercedes cars do.. (noting that some maufactures such as nissan only "recommend" the use uf Premium) and you decide to use Lower Octane gas and think you are doing the right thing, well. I have to say that you are mistaken also but for a different reason..

First for clarification the term "Regular Gas" is outdated as it refers to "Leaded" gas that hasn't been sold in the US for the pass two decades..
so you basically have Unleaded that comes in two flavors and then you have Premium.
The difference between the three obviously is the amount of octane that each contains based on a standard calculation with the ladder representing the highest amount.

SO. the issue with MB cars with Low Octane fuel as Newton stated is the presence of detonation from prematurely burned gas. this of course causes the "knockin" sound and as we all know these cars are equipped with a zillion devices that begin to work overtime to try to reduce this effect resulting in diminished performance of the vehicle. Which I might add results in decreased fuel economy which underminds the whole point of trying to save a few pennies per gallon in the first place.

IMO. if someone filled their tank with 87 Octane as the O/P did and it ran as described as a result of the fuel, I would say that it was the crappy fuel in the first place not the level of Octane. In any case you just drive the thing the 250 to 300 miles maximum you're gonna get till it gets near empty and put in higher Octane. Problem solved.. don;t do it again.... BUt siphoning and thinking OMG my engine is going to need replaceing is just dramatic and frankly a waste of time.

BTW. I'd like to see 1 case of a warranty being void as a result of using commercially sold UNLEADED fuel. I'll bet there isn't one. NOt to say that i condone this, but the point is there is no catagory of "Substandard and "Okay to use fule" otherwise the oil companie would be held liable and who would go to a pump and select "substandard" and fill their car. There is nothing wrong woith any of the three types of unleaded fuel you an get here whether its 87, 89, or 91 ist' all "good" fuel when applied in the right application.

NO one could really be able to have enought evidence of "substandard" fuel causeng a warranty to be voided.. and even if thats the case what part of the warranty would we be talking about? a new car with a blown" rod knocking" What?
I think that's just nonsense and not even worthy of mental entertainment.

As you can see from reading posts here some guy uses low Octane in a lease vehicle.. turns it in, with low miles it will moe than likely be sold as CPO and then what? please with this fuel stuff.

Moral:
Don't be cheap. do what your sticker in your fuel door say's.

m4xm1l10n