Am I mistaken, or when I opened the gas filler cover it said 91 or 93 octane is acceptable? Are you all running 93 or 91 octane and notice any difference? Thanks!

 

You should get optimal performance from either grade. MB says a minimum of 91 octane.

 

I use 91 octane but I wish the car ran on reg 87 octane. In Canada we pay .11c a liter more for that extra 4 octane. Feels like a ripoff.

 

Thanks. We have been putting in a 93 octane. Guess I can save a little money by going with 91 octane. Shouldn't notice any difference in performance should we? Thanks!

 

I use 93 octane. I have been told that using a higher octane means the fuel burns cleaner and therefore increases gas mileage just tinny weeny bit. More importantly it severely reduces deposits in the injectors and sparkplugs which over a long haul saves you more money by not having an additive effect on mileage.

 

91 octane is the middle grade gasoline in Germany. The middle grade in most US gas stations is 89. The only company that sold 91 octane was SUNOCO, but I haven't seen one of them for ages.

 

In many parts of the country, Premium is 91 octane. Where I live in the Northeast (not sure what other areas) Premium is usually 93. As you point out, Sunoco sells 4 grades of gas including 91 Premium and 93 or 94 Ultra. I always put the highest in, whether it is 91 or 93.

 

Where id you get 93? I do not see any gas station in Bay Area selling it.

 

From what I've heard, it's harder to find 93 in some parts of Cali, not sure why. Nearly every gas station in Northern NJ has 93 octane for Premium.

 

In central NJ, Sunoco offers the 91 Octane as Premium and 93 Octane as Ultra. The Ultra runs about 7 to 10 cents per gallon more.
In my previous E320, I used Ultra and thought I noticed a slight improvement over Premium with regards to smoothness and mileage. It may all have been all up in the brain bucket because 91 Octane is also accepted. My '03 E 320 had original plugs with 46000 miles and they were as clean as new with absolutely no signs of deposits or wear.
I am still using the 93 Octane as I feel if it made my previous car run a bit better, it can only be beneficial; for my new car. But then again , it's personal preference whether you want to spend the extra 2 to 3 dollars for a fill up.

 

91 is the LOW octane gasoline in Germany like in most European countries. The middle grade is 95 octane and high end is 98. Have seen 99 octane in some gasoline stations.

Octane rating has big impact in engine performance and the higher you can get the better it works. And I don't belive you save money when you use lower octane fuel. What you save at fill-up you loose in lesser fuel mileage.

 

Octane numbers in Europe and and the U.S. cannot be directly compared. They use the RON (research octane number) method in Europe, in the U.S. we use an average of RON and MON (motor octane number) which yields different numbers posted at the pumps.

 

I tried both 91 and 93 and notice no difference except in the wallet.

 

" the higher you can get the better it works."
is about as far off base as you can get.

The engine is designed with a compression ratio suited for the fuel specified

the higher you go above that slows down combustion and can be more harmful than going to low.


Europe 98 oct is equal to usa 93 and all you and the engine need is 91
or about 95oct in Germany
After that you are pissin money and maybe an engine away.
But hey people do stupid things every day

 

In my earlier post where I say "the higher you can get the better it works" I mean gasoline in the U.S. market. Highest I have seen is 93 octane, most are 91 or less.

I'm not sure about 98 octane in europe being the same as 93 in U.S. Need to do little recearch on that...

 

In S.C., octanes are 87, 89 and 93. 93 currently running 35 cents per gal. higher than regular-used to be 20 cents difference. And it is NOT the brand, it is the retail and wholesale outlets that determine the price.


supposedly M-B engines are designed so that the higher octane will produce higher MPG and more power.

 

I used to drive a lot of miles (not anymore) and at that time always put 87. I have not noticed any damage to the engine, but I have to admit when you put 87 - engine uses more gas, so at the end of the day total money amount spent was equal with 93. BTW, if you browse internet you will find a lot of links that say it doesn't matter which octane to use. Now, like everybody else, I use 93.

 

I wouldn't know about the reliability of data read at the internet, but the scientific fact is that automotive engineers design engines for a particular fuel. Therefore, using an inferior gasoline (87 or 89 octanes in US) instead of the 91 octanes recommended by the manufacturer not only will run your car below standards, but will carry an additives pack inferior in protection of the engine and admission system. On the other side of the coin, going to 93 octanes instead of 91 is trowing the extra cost down the wind since it will not offer any advantages over the 91.

Whoever wishes to defend a different position should publish his/her views backed by concrete facts that are not I heard it from Joe Blow...

 

I don't understand people who use cheaper Gas in a car that requires Premium gas.

Put it this way, M-B is WELL AWARE of the fact that lots of cheapskates don't even buy cars that require Premium, as it's a big turnoff to many. M-B, trying to make as much money as they possibly can, clearly wouldn't want to shoot themselves in the foot, by saying "Premium required" just for fun.

Clearly these motors are designed for that. For a Leaser, maybe they won't care of the potential harm that gets done to the motor in the long run, however, even for said Leaser, if something were to happen to the motor under Warranty, M-B could very well blame it on the Gas, and you're S.O.L.

The car will also retard timing, to compensate for the lower Octane, which means that it's keeping itself safe from "pinging".... Which means, again, the gas isn't good for that motor, and it also means, you're getting weaker and less efficient engine performance out of your car.

And finally, it wastes more Gas, I'd wager, that you probably make it ahead financially overall by using 91, instead of letting your motor drink 87 more heavily.

On the flip side, putting too high of Octane in a car that requires, for example, 87, is harmful for the motor, hurts efficiency, and really wastes your money.

Oh, and the weakest argument is "not noticing" a difference. Of course you won't notice, this stuff is so minimal in the short-term, and you won't hear the engine knocking, due to the retarded timing. It's a "build up" effect, in that it builds up against your walled (using lower Octane), and builds up negatives for your motor.

Just use the right Gas, that $2-3 your so intent on saving at the pump, will end up finding its way back inside your wallet in the back-end, and then some.

 

http://www.wanderings.net/notebook/M...sWorthTheMoney

 

I know this is old, but around here there is no 91. It's 87, 89 and 93.

 

Well you could put in like 1/2 a tank of 87 and 1/2 a tank of 93, lol.
I did that once a long time ago and my bank shut off my credit card thinking it was fraudulent charges because why else would someone use their credit card twice at a gas pump.

 

I never really looked at what octane it is. I just put in the premium gas. It is about 35 cents higher than the low grade.

 

Have you tried the 89? Do you get any pre-ignition issues or run on after you shut it off?
We pay 12 cents per Liter more for premium or or about 52 cent USD per gallon for premium in BC.

 

Agreed.

My local station is $2.76 for Regular (87) and $2.93 for Premium (93).

At 15 gallons a fill up, which is usually every two weeks for me, the numbers are $2.55 every two weeks or $5.10 a month for high octane gas.

When my budget cannot handle $5.10 a month I will selll my Mercedes.