I would suggest using the standard copper core bosch plugs for your car.

Platinum plugs may help other cars, but most have found they don't do much in a benz.

I have standard copper core plugs in my 300ce, my brother uses standard copper core plugs in his range rover instead of those +4 plugs, and his car runs much better now than it did with the +4 plugs that have the 4 arms over the electrode.

Check fastlane or partsshop. you should easily find the right standard plugs in there for your car.

Alon

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'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon - Sold
2006 E350 Wagon - 368 - Dead
2015 GL350 Bluetec - 197U