Mattsuzie,
What they mean be PREMIUM is a minimum octane rating of 91.

Steveblf,
Great info! You're so clever.

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

Any words of wisdom out there on the old trick of adding not more than 2 moth balls (naptha) to a tank of gas to raise the octane rating by a couple of points? I've never tried it, but I'm told that it works and have always been curious.

__________________
'76 240D-Sold
'78 240D-Sold
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet- under restoration
'86 560SL 124K Miles-Sold
'94 320E Wagon, 74K Miles-128K Miles JUNKED
'06 E350 Wagon, 84K Miles
07 SL550, 14K Miles

Correct me if I am wrong, but all US pre 1986 cars require no more than 87 octane fuel. All newer models except for the 1986 190 2.3 require 91 octane. If your car runs bad on 91 octane, something is wrong. I would suspect an incorrect timing problem if all "wear" items are fresh.

Ron,
To answer your question,I know a guy who put 2
mothballs to his gas believing it will raise octane rating,guess what happen? It clogged up his fuel
system.Some say it has to be disolved before
adding it to your gas.Never tried it.Never will.
Clauser1

and was so nervous about "flooring" it that I will never put anything less than 91 in it again (the E320). This weekend while in the Commerce, Ga area I found some 105 octane "racing fuel" sold at a gas station right off of I-85. It was $3.99/gallon but I'll bet it was some good stuff.
Jim
'85 300D
'95 E320
'97 CRV

Living in the midwest, the highest octane I can find locally is 92.5, but it contains ethanol. I have been told to avoid gas with ethanol as your engine "reads" it as octane thus negatively effecting performance.

What are your opinions of gases containing ethanol?

__________________
Brian W.

01 S55 AMG Silver
01 CLK55 AMG Silver

Brian,
I posted a thread about ethanol& methanol not too long
ago,and I never got any response so,I ask a dealer about it.
They said that we can run fuel w/10%ethanol or 3%methanol
but cannot be mix together.They are not compatible.In that
case I stayed w/Shell which contains no more than 10%
ethanol.My car likes Shell the best anyway.

Clauser1

Thank you Clauser1, I may try running the 92.5 with ethanol for a tank or two.

One more question, you know of any good MB tuners in the Chicago area? Someone with turbo or supercharger experience? I ran across one webpage, but damned if I can find it now!

Thank you!

__________________
Brian W.

01 S55 AMG Silver
01 CLK55 AMG Silver

Brian,
There are so many good MB mech.in Chicago area.
But most of them are very expensive.The one who I trust
my car with,is European Am.Motors.Located at Lincoln&
Addison.3541N.Lincoln Ave.Chicago,Ill.60657
Ph.(773)929 4288 or 9293764.Ask for Rudy an Austrian guy
whose very knowledgeable in MB(his specialty),and the owner
of the facility.See if he can help you.
Good luck!
Clauser1