Learn how to use the "SEARCH" feature of this board. There is tons of info on spark plugs. Study the posts that seem relevant and make sure you understand any risks you may encounter before you jump in there. ONLY use the plug specified in your owner's manual. If you don't have an owner's manual, call the nearest MB parts counter and get the part number from them. Don't trust Autozone or any other McParts place to get you the right number.
Good Luck, Dan

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2012 E350 Bluetech