Bosch W9DC spark plug alternative?
 

Can someone suggest replacement for hard to find Bosch w9dc spark plusgs for my 77 450 sl? closest is W9DC O. Is this a good replacement and what does O stand for? Any help appreciated. Abe G

Ngk -bp5es

Answer:
 

Item Number: 0031591003
Main Category: MERCEDES BENZ
Sub Category:
Description: W9DCO, BOSCH, these are "NOT" resistor spark plugs









Have a great day.

The "O" stands for a larger diameter electrode. If you go to the dealer and order plugs for you car the W9DCO is what you will get.

John Roncallo

I have a small supply of the Bosch Super W8DC plugs.

- Steve

solution to Bosch spark plug problem
 

Thanks to the experts like Arthur Dalton, W. Hunter and john, problem solved! ( I dont know what us amutaurs would do without them) Thanks again, bought some nkg bp5es and improvement right away! Bosh doesnt show any of the W series on their website, although the dealer does have the O WD. I have had many excellent suggestions from Tech help on the forum and appreciate same. Regards, Abe G PS My few contributions have consisted mainly of WD 40 use. Hit my 80th birthday last week.!! keep up the good work.