Another question about the 95 E320
 

Just bought the car. 87K, 95 E320 wagon. Stupid question, but the book calls for 91 octane or higher. Is this something I should adhere to? I burn 87 octane in everything else I own without problems. I don't think it actually makes all that much difference between 3.50 and 3.70 a gallon so I am happy to spend the difference if it is legitimate (paying 4.03 for dino diesel and 4.50 for biodiesel in the other MB right now so gas seems like steal:)). I'm never sure about some of these recommendations and the reasoning behind them. If legit then cool, fair enough and move on but I never know if say a board member of MB at the time also an Exxon board member!

I would use the 91. I have run 87 in my 300E and noticed it ran poorer. It won't blow the car up if all you can find is 87 for a one time fill up.

When gas is at these prices--what's the difference?!? Go for the 91...

-GH

That engine is a high compression HFM/SFI system with ECU capibilities to retard engine management parameters for the lower octane fuel, but with noticiable performance deficiency...so you gain nothing and wind up with a dirty running engine.

Go even higher ....
 

up the octane scale. In my area 93 octane Shell is always the same price as other brand's 91 octane. I swear my M104 runs better and gives better gas mileage with the 93 octane.