nickia

I just realize this car requires 93 premium gas but most of the gas station in Toronto only have 91. Is it ok to fill it with 91?

gOt BoOsT

91 is fine. use 76 or cheveron

C63newdude

I have been running 91oct on my car since new. I am located at elevation and with temps in the 110 degrees. If I can run it like that you can run it like that. I am more prone to get some knock though..

arctichaze

Shell is good too. Stay away from the cheapo stations like Arco.

chief63

I was putting 94 since it said 93 on the gas door, I've tracked the car on 91 and 94 octane on the same track, no difference at all. Reaching same top speeds. Stopped putting 94...

Mort

The fuel door has the European RON (Research Octane Rating) of 98 (min 93). This is a different rating than we use in North America which is the average of (RON + MON (Motor Octane Rating))/2. In North America the octane number (posted at the pump) must be 91 minimum.

RON 93 = (RON + MON)/2 91.

I have no idea why MB puts the RON octane rating on the fuel door for North America as it is just confusing to everyone here.

chief63

Thanks for making it clear, I found a good chart online for RON (Europe) MON (alternative test method) and PON (America, which is a mix of RON and MON)

http://www.btinternet.com/~madmole/R...RONMONPON.html

So if this is indeed for Europe, 93/98 in PON means Min octane is somewhere around 89 and max 94.

91 PON as we see it here in America is 95 RON 95+87 / 2=91

Mort

That is close to what it says in the Owner's Manual.

P.223 Only use premium unleaded gasoline with a minimum Posted Octane Rating of 91 (average of 96 RON / 86 MON).

PON = Posted Octane Number. I think the formula in the Manual is a typo obviously and should be: (average of 96 RON + 86 MON) = 91 minimum PON.

Just a little different than what you found. I am not sure which is more definitive. Maybe there is more than one way to mix the fuel to get 91 PON.

I have no idea why they put RON (min 93) on the fuel door if it is not = to 91 PON.

There is futher information on fuel requirements on P. 354 of the Owner's manual and has information on reformulated gasoline and alcohol blends. It also covers procedures to follow when switching fuels.

ZephyrAMG

We can just combine my thread and this thread. Looks like we posted within minutes of each other...

Good info guys. Thanks a bunch.

I love it when you freekin geniouses chime in...It's like having your own personal Alfred in the batcave...

220S

http://www.torquecars.com/articles/f...ne-ratings.php

BlackCherryS

I appreciate these posts fellow MB brothers, alot of people overlook the use of gas and it's different fuel grades. It's a dangerous thing to take for granted what the dealership actually recommends for use but I for one pay close attention to every minor detail and I stick to 93 over here in the US, I'm in Virginia where you will find plenty Chevrons, Shells, and Texaco's so after doing some research I switched from BP to Chevron or anyone of the top-tiers and will remain diehard with a top-tier for the duration of my motor-vehicle use!

jvanbrecht

Any particular reason you switched from BP. Because of the recent handling/cause of the spill, or you don't like their gas. They actually have a good quality gas. If your boycotting them because of the spill, all you are doing is hurting a local business who only franchises with BP to get their gas. Gas sales to local franchises for BP amount to a total of about 4% of their profits. The majority of their profits come from industrial sales, oil and its by products are pretty much in everything that has plastic. Castrol brand is a BP product as well. Not to derail the topic, I just think its silly to boycott a local business, when the prices and quality of the BP gas are low and high quality.

I will end my thread derailment.

BlackCherryS

No boycott on my behalf, just did some research and it didnt come up as a top tier gasoline brand, that's all. I actually don't have a problem with BP with their situation. Things happen and I actually feel sorry for anybody that gets their back against the wall, even the big guys can fall too!!!

nickia

haha yea. It's so awesome to have a wicked support fourm

Even Money

For a stock car, 91 or 93 would be fine. As you tune the car, advance the timing, etc., detonation becomes more of a factor. So, a higher octane number is more resistant to detonation.

Burning a higher octane numbered fuel doesn't mean you get more HP, it only means you're able to get more out of it with a proper tune.

badblackbenz550

my list

1.Shell.
2.BP.
3.Exxon

i don't put anything else in my gas tank.

Even Money

Suppliers are known to share piplines. In fact, a chevron station could be selling gas refined by BP, shell, or someone else. All gas is required by law to have detergents added to it. So, the diff between techron and shell is probably minimal, i've used both. One will likely clean as good as the other. The better thing to watch out for is filling up at an old station with sediment build up in the tanks, slow pumps that indicate filters are clogging up. Find a relatively new station with one of the known suppliers.

MB_Forever

Actually, BP's gas was ranked in the lowest 5 in terms of quality gas back in 2005. I don't know how they're doing right now though. I always like to stick with top-tier gas as well: Chevron, Shell, Mobil, etc...

jvanbrecht

Well, I live in the DC metro area as well, I generally have a number of options for gas, atleast 3 to 5 stations of each brand within 5 miles of my house, so while I will use BP on occasion, I generally go with whichever one is cheaper.

The one thing I avoid, are the WAWA's, they have cheap gas.. but its 92... WTF!!.. Thats an odd octane.. no idea who they get their gas from, and I suspect its mixed 91 and 93......

gsrjc

I use sunoco or shell.

hingkit

Hate to bump such an old thread ... But...

I found 94 octane up here in the north (Petro Ultra) and wow.
There is quite the significant difference from my generic "premium" (91 octane) ... difference I can feel. Everything is more responsive ... From this day forward quality gas only.

otakki

Good bump since it brought up some info I didn't know about.

Shell's V-Max supposedly was formulated by Shell in conjunction with Ferrari. Wow, didn't know about BP's quality in '05.

Sure would love to see some Chevron close to the greater Chicago.

Pickles

Hello from Oz.......I am confused!
Down under, we have 3 fuel "ratings"...98, 95, & 91.
I use BP Ultimate 98 when I can, but if I can't get it, then I'd have to use 95.
The manual says to use 98.
What do these ratings...98,95,91 "equate" to, in U.S. "definitions"?
Cheers, Pickles.

nkc

In nigeria, we have notin but ' fuel' could very well be ron 90 or 80 but as long as the amg is powering i care less..... Lol

Guilty

I guess 98=93, 95=91, and 91=89 lol