spark plugs
Thread Starter
Super Member
Joined: May 2003
Posts: 560
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From: Walnut, CA
MB 1990 300E
spark plugs
So its about time that I change my spark plugs, and I read that everybody is using the bosch h8dc super copper spark plugs right? Where do i find them? Doesn't seem like a lot of online retailers have them, and I also read that people who did order the h8dc still got the platinum plugs. What are you using?
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From: Petaluma, California
1990 300e 3.0L
I'm using the cheap Bosch copper ones - took the Platinum's out (tried singles, then +4's which really sucked) because I thought they ran worse in this engine. I could not find the H8DC plugs ; and Napa sold me HR9DC's ; but I hear the 'R' (extra resistance) exceeds MB's recommended plug specs ; and gives you a weak spark.... 
Hope some other members can offer us both some more advice on this issue, as I would love to know where to find the H8DC plugs as well ; but I think the T20EP-U Denso (non R) plugs might work...
Hope some other members can offer us both some more advice on this issue, as I would love to know where to find the H8DC plugs as well ; but I think the T20EP-U Denso (non R) plugs might work...
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From: Long Beach, Ca
lots of cars
it doesn't say out of stock so i guess they have them....
http://www.partsamerica.com/ProductD...artNumber=H8DC
http://www.partsamerica.com/ProductD...artNumber=H8DC
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you can get them at your local parts store. theyll try to sell you platinum plugs and tell you that somehow youll have better spark or whatnot. ignore them.
their computer will tell them which are the correct ones.
their computer will tell them which are the correct ones.
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From: Long Beach, Ca
lots of cars
they will always try to sell the h9dc...so don't trust their computers...My friend works at kragen and they don't have the h8dc on their system. First ask if they sell bosch supers and then give them the part number...
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1994 White an Grey E320 "Shado"
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Joined: Nov 2007
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From: Petaluma, California
1990 300e 3.0L
Do they sell them at NAPA Autoparts? The HR9DC must be in the computer ; because that's what they sold me
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Thread Starter
Super Member
Joined: May 2003
Posts: 560
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From: Walnut, CA
MB 1990 300E
I received the spark plugs I ordered fro RockAuto the other day, but I dont think they sent me the right ones...
On the website it says H8DC which is what I wanted, but on the box it says HR8DC+. It seems like these are the platinum ones with a copper core rather than the copper plugs. Are these the same spark plugs??
On the website it says H8DC which is what I wanted, but on the box it says HR8DC+. It seems like these are the platinum ones with a copper core rather than the copper plugs. Are these the same spark plugs??
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Joined: Nov 2007
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From: Petaluma, California
1990 300e 3.0L
Just FYI - I called Napa the other day ; as well as Kragen Auto Parts , and Advanced Auto Parts... Not one of them has the h8dc Bosch Super's ; and they couldn't find one set of 'non resistance' plugs in (any) brand. 
Kragen said they could order the Bosch H9dc0 Super's for me @ $4.99 a piece but couldn't find h8dc in their system. I noticed my plug wires run at 1k of resistance per plug - so obviously non-R plugs are the way to go.
http://www.partsamerica.com/ProductD...pe=960&PTSet=A
Unfortunately, I went with another 'in the computer' recommendation NAPA auto parts ; and got Champion rs12yc copper cores which I am not impressed with at all. I would love to know where I can purchase these locally, or if there is an alternative that works
Kragen said they could order the Bosch H9dc0 Super's for me @ $4.99 a piece but couldn't find h8dc in their system. I noticed my plug wires run at 1k of resistance per plug - so obviously non-R plugs are the way to go.
http://www.partsamerica.com/ProductD...pe=960&PTSet=A
Unfortunately, I went with another 'in the computer' recommendation NAPA auto parts ; and got Champion rs12yc copper cores which I am not impressed with at all. I would love to know where I can purchase these locally, or if there is an alternative that works
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From: Long Beach, Ca
lots of cars
I will hunt for them locally and if i find a good source i can ship them out to everyone..lol..
By the way i have champion RS12YC copper plugs which should be the same as the h8dc
By the way i have champion RS12YC copper plugs which should be the same as the h8dc
Last edited by YNVDIZW124; Dec 23, 2007 at 02:54 PM.
