Re: Spark Plugs

Iridium is good... they last alot longer. Please remember factory plugs 
should last 100.000 miles. These plugs are not copper.

Platinum single electrode is okay substitute. I don't recommends putting 
anything other than factory plugs.

If the factory plugs comes with two electrodes, then you can put two 
electrodes in or equivalent single electrode oif the same grade... do not 
downgrade.

I don't remember what year MB start to use these long lasting plugs... 
whatever it is, these plugs are not every year tuneup parts. Even copper 
plugs on older cars can last 2 or 3 years without a problem. I would say 
roughly 30,000 miles.