Hi,

I have a 1990 MB 300E and have Bosch HR9DC+ (#7978) Spark Plugs currently installed in my car. I received a couple of boxes of Bosch HR9DC (#7578) and was wondering if it was ok to use these for my next tune up? What is the difference between the two?

It seems that they might be old stock.....I am just guessing because they are not "+".

Any information would be greatly appreciated!

Bob

Do a search. This is probably one of the MOST discussed (to death) topics on this board.

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-tp


1990 300SE "Corinne"- 145k daily driver - street modified differential - PARTING OUT OR SELLING SOON - PORTLAND OR. AREA - PM ME FOR DETAILS
1988 560SEL "Gunther"- 190K passes anything except a gas station
1997 S420 - 265k just bought it with a rebuilt trans. Lovely condition

tp,

I did a search and spent much time sifting through the resistor/non resistor issue. I had trouble finding the answer to my specific question about these two resistor plugs so I took the easy way out and addressed the forum. I will keep reading threads I am sure you are right it's there.

Thanks
Bob

R is the resistor plug. No go.

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'O=00=O'
bmw 2002.
long live the legend

...

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

Ok I am convinced.........get rid of the resistor plugs! The car was running fine using them so I RESISTED (forgive me) the quest to find non resistor plugs. It looks like the NGK (BP5EFS) sparks are a good replacement for the Bosch.

Does anyone have a good source for the NGK or equivalent replacement?

Thanks again.

The MBUSA Classic Center in Irvine stocks the correct non-resistor NGK plugs. Last time I checked, Fastlane Phil did not.

http://www.mbusa.com/mercedes/MBHome.html#/onlymbMenu/classicCenter/

__________________
1988 California version 260E (W124)
Anthracite Grey/Palomino
Owned since new and still going strong and smooth
MBCA member

Past Mercedes-Benz:
1986 190E Baby Benz
1967 230 Inherited from mom when she downsized
1959 220S Introduced me to the joys of keepin' 'em goin'

There are only 10 kinds of people in the world--those who understand binary and those who don't