All I know is this.I have a 1996 E320,Car ran like crap.Changed plugs to Bosch Platinum 4's Ran worse.Changed to Bosch Copper Non Resister Plugs F8DC4,about $2.00 each,runs like new again.Did nothing but changed to non resister plugs.

How about for my m103,Mercedes dealer says only RESISTOR plug available,and it will be okay to use them.?????This apparently is sanctioned by Mercedes Canada.

So before they say it's not okay to use resistor plugs,now they say it's okay?

I searched high and low and found some non-resistor plugs in the ebay.co.uk.Now they are in my car.
Next time around,there wont be anymore?

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Tom 2010 C250 4-matic Sport (Canada)

I, too, have heard of this situation through legend and folklore. Obviously, as a mechanic by trade you can speak from direct experience. Though I’m not sure how the arcing can be worsened in the distributor/rotor interface simply by using resistor plugs.

However, your point about the WIS stating a maximum of 5Kohms resistance is interesting. While I do not have the WIS available to me, to does provide another piece to the explanation puzzle.

Yes, I have searched… and searched... and searched. The problem is the sheer amount of emotional flotsam on the subject. But more importantly, there is the possibility that as time goes on, opinions and capabilities change. MB Engineers change direction as any other engineering team does. They and their vendors make advances that allow backwards compatibility. Further discussion may bring forth a new revelation or hard, objective data that explains the old method. Continual questioning is a natural tendency for us engineers. Sorry. At least this thread gives the Diesel guys something to chuckle about!

Interesting. My experience – anecdotal like yours – was that when I installed Bosch Platinum+4 plugs in an already good running SL600, that the engine ran better. I freely admit my experience is a subjective statement. But it does show that people can have different experiences with the same product. For the record, I did take out the Bosch Platinum+4 plugs and installed standard, off-the-shelf OEM parts. It was an action based upon emotion, as opposed to data.

Hmmm… Playing the Devil’s Advocate, dealers do not always provide accurate information. Then again, they may know something we don’t. Regardless, are you saying the dealer could not supply the ‘factory’ spark plug for you vehicle? Doesn’t make sense.

Again everyone, I’m not stating one plug is better than another or that resistor plugs are better than non-resistor. I only want to find conclusive, objective data that says one way or another. This is the same discussion that many of us had when synthetic oil was first introduced. Now look – it’s the standard! And how many of us poo-poo’d synthetic when it first came out, simply because it was ‘different’. Same could be for plugs. Discussion is always healthy.

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MBCA Member #B012089 (Lone Star Section)
OBK Member #47 (W123 Division)
'96 SL600 (105K) Triple Black - Mein über-Fräulein
'79 240D (292K) Yellow/Saddle - Mein Spielzeug
'01 ML430 (123K) Black/Saddle - Wife's Ride
'94 SL500 (164K) Green/Champagne - Daughter's Dream
'73 450SL - RIP
'86 300E - RIP
'88 420SEL - SOLD
'94 S320 - SOLD

Please don't generalize.
M-B specifies resistor plugs in some engines & none-resistor plugs in others.
So, if you want to make your own rules go for it ( and live with the consequences ).

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2007 C 230 Sport.

this ***** is confusing. heres a question: why doesn't someone just ask mercedes? like their engineering team. heck I'm gonna email them and see what their official response is.

roar.

email sent to the Classic Center. We'll see what they say...

__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
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93 300E 195k

A simple question: I have installed Bosch platinum plugs #4020 in a 110 engine - there is no "R" in the number. (I could not care less about radio interference as all staions in the SF Bay Area now suck anyway). So are these plugs resistors or not?

Have you tried getting non-resistor plugs from the dealer for a 15 yr old W124?Last time I went to the dealer Mercedes Benz Markham branch,they gave me RESISTOR plugs?
10 years ago,they told me resistor plugs were bad for my car.So what gives?Are they trying to kill my car and sell me a new one?
I declined and got mine in the UK before I knew about their avail here from this site.

Manny if you know of any source of non-resistor plugs in Ontario,please let me know.!!!!!!!!!!!!

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Tom 2010 C250 4-matic Sport (Canada)