It's stated very clearly in the owner's manual. If you're in an emergency and can't find 91 though, you can fill up with a lower grade fuel and the computer will compensate. However, you should go back to 91 octane or higher the next time you get a chance since running the lower octane fuel is not so good for the engine over the long run.
A lot of places in NJ that have 91 as the mid grade gas and 93 as the premium and 89 as the regular. Others in NJ are 87/89/91. I usually fill up with the best stuff available no matter what the octane listed is, because you never can tell what the REAL rating is...
they use to measure the octane of the gas. RON, etc. MB does specify this as well in the owner's manual so that there is no ambiguity. Yes, filling up with the best stuff is one way of taking the guesswork out of it :-)
Linear Mode
