I believe the consesus is that the platinum plugs CAN leave platinum deposits in the engine which isn't good for it. I don't know if that means it will put platinum deposits in, but it can do it if the conditions for it to happen are met.

I also think essentially that the copper plugs do just as good of a job as the platinum ones.

I'm not a tech, but I'm more than willing to follow the advice of my fellow members here.

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