Hey

New at the forum therefore I do not know if this has been discussed before. I am wondering what spark plugs I should get for my car since there are several aftermarket like Bosch platinum +4 which have great claims. OEM is a single spark Bosch plug. They also have the new Fusion (platinum and Iridium). Should I just use the stock plugs? I think I have read that the Bosch +4 do not work well in Mercedes-Benz? Any help...

 

What I'd recommend are the fine-electrode double platinum plugs (or iridium plugs if you want to spend the $$ for those).

The double platinum plugs provide a surface that won't have gap erosion which will happen with conventional electrodes.

Depending on the model year, Mercedes recommends a 4 to 5 year interval if you don't reach the 100k mile interval by that point. You get soft carbon build up and this reduces the efficiency of the plugs.

I replaced mine after 5 years (only had 33k on the odometer) and while my performance was fine, I noticed the mileage did go up a little bit, and perhaps a somewhat smoother idle than before.

I used the stock bosch platinum plug (double platinum tip) the owner's manual recommends - the price wasn't too bad on those either.

 

I just changed mine with NGK Iridium IX and they are worth every penny. No complaints here and feels a lot better!

 

I've got the Bosh +2 and get misfire CELs every now and then. I think it's been discussed before and people have the same issues.

 

I use NGK Iridium IX also. Super smooth. Pulls hard right to the redline. It came with Bosch platinum 2. It made the car bog slightly@ 2600-3200. It also stars up much quicker now.

 

Thanks for the feedback! My CLK430 is 2001 and i am trying to get the best replacement parts. I will look into the NGK IX spark plugs. They look similar to the stock plugs except for the iridium. Has anybody tried the Bosch +4 Platinum? What price do the NGK run at?

 

I used them(Plat+4) for the past 4 years in other cars. They work. Just not as good as the Iridiums. At the time time I bought them they were best I could find. Now an Iriduim will out power and more importantly outlast even a plat.+4. I know you hear people B.S. about what guys use, honestly Iridum's are worth it. Research the different Iriduim's also before you buy. There is a big difference.

 

So Iridium it is!

NGK, Bosch, and Champion make Iridium for Mercedes...so I guess the NGK are leading the pack since they have been proven in CLK430. anybody else tried another iridium plug on their CLK430?

 

[QUOTE=jalberto;2067395] (So Iridium it is!

NGK, Bosch, and Champion make Iridium for Mercedes.)


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>>_>>__>__>_>> I used denso2 or 4 but when I pulled mine out they said Bosch iridium dr8 not sure the rest I can look up if needed ..
Clk320 year 2000 I wasn't sure if they were original but I'm sur iridium didn't come out until after 1999-2000 anyone used denso, platinum what happens .... I was getting a abs bas. Light once in awhile before changing the plugs and once after.... going to replace the voltage regulator in alternator just for prevention maintenance.... rambling now ... this was to confirm Bosch has iridium plugs that work very well in clk320 w208 ...not sure if it was even time to change mine. They were iridium so black doesnt mean done I'd think. Again denso platinum anyone ttied them yet?!

 

The metal in a spark plug is there for one reason: to turn the energy from the coil into a spark. ANY metal that conducts electricity could be used for a spark plug, but some metals are better than others. It’s widely known that copper plugs have the best short term performance. That’s because platinum and iridium don’t conduct electricity as well and they’re more likely to overheat. That said, no one uses copper because both platinum and iridium plugs last MUCH LONGER. That’s because copper wears quickly in comparison. Anyone who’s swapping plugs every six-thousand miles should use copper, but none of us do, so copper is out of the running.

That leaves iridium and platinum. Both have 100,000-mile longevity but iridium conducts electricity better and is ultra-hard. This allows iridium plugs to have a smaller tip which will produce a more concentrated spark. Which plugs would I get? I buy a lot of stuff from Autohaus AZ and they sell Bosch iridium and platinum plugs for the same amount – $5 a plug, so I’ll probably use iridium on my next change. Practically speaking, the M113 has dual plug head and the coils are MSD (multi spark discharge) units. Provided the OE wires have been changed, I don’t think igniting fuel is a problem in these cars. Most people have change their wires, right? Bosch wires are inexpensive and they're a normal wear part.

 

My last change I went with NGK Iridiums and Wires, I could be wrong but after the change I felt a decrease in performance. I'll go back to the Bosch on my next change.

And who brings back a thread that's 9 years old...lol

 

That settles it for me. I'll stay with platinum plugs. With a dual plug head, it sounds like iridium may a solution in search of a problem.

 

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Effective age, condition of mechanicals, weather, temperature, altitude; and most importantly fuel grade can effect overall tune and how it "feels"

But #'s don't lie or exaggerate personal taste
I.E. O2 sensor readings.
Mileage, mpg and 20-60 mph acceleration times

I have Denso Iridium in our R230 with 15k mi. after replacing plugs. Couldn't be happier. I picked up 2mpg. Never a miss or flat spots
W164 20k mi. after replace. Picked up >3 mpg.
Runs great. I drive both these M113 V8's like I stole them.
I'm not going to say Iridiums are for everybody but they work better than Platinums I've used including our gone but not forgotten 208

Although personal choice and objectivity is not as relative as hard facts and #'s the bottom line when choosing replacement parts is always personal choice.
Choose well. Do some unbiased research. Don't be swayed merely by online chat.
Good Luck

 

The Bosch Plugs I had were fairly new, I use 95 Octane gas, car only has secondary cats, no primary cats on CLKs in Japan, low mileage, and a Dyno to prove that I lost HP. Any Questions.

 

I think we covered the Octane rating thing being international ratings differential being higher than U.S. around the same time as the spark plug debacle.

If a spark plug causes a loss on a dynamometer most likely cause is deposits or carbon buildup. Although replacing a different heat range will signal the ECU to cut ignition timing on any motor especially one with any mods. So wether the plugs were even Copper to Patinum may be a loss as well. Not a +/- for Iridiums just a difference in output not relative unless you tried Copper, Platinum and Iridium on the dyno at the same time. The difference between morning and afternoon can effect dyno results
Like I mentioned, every owner has a different set of circumstances but an Iridium fires a hotter spark according to manufacturer informational docs.
The issue may be the actual area of electrode is larger on a Platinum and may be less prone to cut timing, misfire or lack of voltage than an Iridium due to low energy factory spark plug wiring and/or ignition system variances not being able to properly fire a standard motor or one with even higher performance requirements

 

Hmmmm . . . . . . . . . a hotter spark . . . . . . .

If the gap is the same on two plugs, the only way one spark can be hotter (temperature wise) is if the spark duration is longer on one plug. Since iridium plugs require lower voltage levels to spark, they should have a longer duration, so their spark should be hotter. That’s great for non-MSD (multiple spark discharge) ignitions. HOWEVER, that long duration comes at the expense of creating multiple sparks. That's because there is less time available. The question then becomes, is the fuel more completely burned with fewer long duration sparks, or multiple short duration sparks? I honestly have no idea. There's too many variables (mainly combustion chamber design), BUT the dyno knows. I can say this, these cars have capacitive discharge systems. CDs produce BIG short duration sparks. Maybe, just maybe, when designing the combustion chamber the Mercedes powertrain engineers expected and planned to have multiple sparks.

In some combustion cambers (cough cough 3-liter Porsches), MSD works much better than single, long duration sparks.

 

Truth, M113's have twin plug type ignitions by MB own definition. Instead of single spark firing multiple times the concept is a Twin plug Ignition system. They fire twin spark plugs (16 altogether) per cylinder.

An Iridium is better suited to this type of firing due to the increased spark and a faster/sequential firing from the single pack coil with a very short replenish time.

The increased spark is the whole idea behind making the best plug which is to get the electrode as small as possible. A much larger Platinum electrode gets in the way of the the spark kernel and causes a temperature drop and a less efficient combustion.
http://www.globaldenso.com/en/produc.../features.html

Iridiums came stock on our W164 from MB. Truth.

Platinums were used before Iridiums were mass produced at a cost effective price.
When Platinums were originally marketed, Copper was touted as best by oem users.

 

I just Eneos 100 Octane gas. If I remember correctly Japan 100 Octane = 95 US. I pretty much Dyno'd my car after every performance mod. One being after installing the NGK Iridium Plugs and wires. What I can't remember is if at the same time I also upgraded my engine coils to Okada Projects.

 

The first thing I wrote in my last post was “If the gap is the same on two plugs". The link you’ve attached describes two plugs with different gaps. If two plugs have the same sized gap, the spark size will be the same. Duration can change, but not size.

Let’s be specific about what we’re talking about. You’re using the term “twin plug ignition system”. I remember quite clearly Porsche 964s use a factory twin plug ignition and a lot of earlier 911’s have been modified to use twin plug ignition. In a twin plug ignition system, each cylinder has two spark plugs and the two plugs for that single cylinder fire at the same time. Although there are dual plugs, the CLK’s M112 and M113 does not use a “twin plug ignition system” and Mercedes-Benz does not call it that.

Mercedes-Benz calls their ignition an “offset-phase twin-plug system”. That name is a quote from the Mercedes-Benz press kit. Here is how the system differs. On a CLK, each cylinder has two spark plugs that are fired from a single coil unit. Those two plugs do not fire at the same time. The fact that they do not fire at the same time makes the single coil an MSD unit. How do I know they don’t fire at the same time? The CLK's original Mercedes-Benz press kit expressly states the plugs do not fire at the same time and the ECU varies the stagger based on engine load and speed.

As for iridium plugs and spark replenish time, some may be confused by your wording. The ECU’s ignition logic determines when the ignition fires. While waiting for the signal from the ECU, the capacitor builds a charge. When the signal is received, the capacitor passes the charge through the coil, which ramps up the voltage and passes the charge to the plug. The coil and capacitors determine the time required to replenish the power sent to the plug. Then the plug fires

As for the W164 having platinum plugs, what ignition system does it run? If it’s not the offset-phase twin-plug system used by Bosch ME 2.0 or 2.8, there may not be the semblance you’re expecting.

 

Very wordy and sadly off base. Look up M113 W164

First of all, Our W164 CAME with Iridium with a MB STAMP.
NOT Platinums.
Regardless of gap, name of ignition (which you originally mis named as MSD)
Making references to gap and Porsche ignitions names and replenish time etc, etc is fascinating but seems purposeful to clouding true facts about Iriduim plugs.
Stop with the gap nonsense please. In terms of basic comparison it's irrelevant.
Not sure what you extrapolated from a Denso doc regarding gap but what the jist was basically;
Platinums cannot equal the size and shape of a spark because of the electrode shape and size given to OEM low level coil packs. QED
Bottom line is and always will be even Mercedes concedes Iridiums are a better choice and provide a higher efficiency level

Maybe you know more than Mercedes does about Porsches but I don't feel your abstract. I'm Sorry

 

I misnamed the ignition? It sounds like you're in over your head. MSD is an acronym that stands for multiple spark discharge. In this case it's a type of ignition system, its not the "name". Nobody's insinuating that Holley is an OE supplier of Mercedes-Benz ignitions.

The "name" is what Mercedes-Benz calls it - an “offset-phase twin-plug system” - something you didn't know until I posted it. But hey, if you want to call it a twin plug ignition system and fantasize about both plugs firing simultaneously, don't let those wordy Mercedes-Benz documents confuse the issue with facts.

Similarly, don't let Jimmy's dyno numbers interrupt your wet dream. After all, those are more wordy facts. Nope, your truck has iridium plugs, so that's the final word.

Always a pleasure Gahtoe.

 

"Practically speaking the M113 has dual plug head and the coils are MSD (multi spark discharge) "

Misdirection has served you well. I can't take credit for things you incoherently put out there.

I did glance at some offbeat, pirated garble some self absorbed Porsche-file wrote a few years back but no actually I did have the opportunity to research M113 ignitions about the same time this thread was started.

Since then I've moved on. Maybe you should as well.

 

When I did a spark plug change I haf the Bosch Iridium my car is 16 years of age and with 150k miles. They looked that old but since iridium I couldn't be sure since the tips last so long.

 

Below is a picture of four cars at my house. Three are Mercedes-Benz; the black one, the white one and the silver one. The silver one is a 2002 and I personally did the plugs twice. I changed the original plugs, and they were Bosch double platinum. The white car is a 2010. I personally did only plug change that car has ever seen and they were Bosch double platinum. The black one is a 2016 and I have no idea what kind of plugs it has, so forget about that one. That's not a slight on the iridium plugs it may or may not have, just that I don't know what's in it. I'm confident Mercedes selected the best plugs for the car, whatever they are. If you’re saying your 2000 model year CLK came stock with iridium plugs and they lasted 16 years without showing any wear, that is simply amazing.

 

They must have been done at 75k since the car wasn't showing any signs to be concerned and the Carfax shows it has been serviced at mb dealer until 90,000 miles mark I just noticed.

>>> any other suggestions for maintenance.?

Spark plugs√
Z-MAX fuel additive√ (fuel filter ordered)
Soft top hydraulic lock cylinder 0ring repair√
Air filter, cabin filter√
Coolant flush√
Transmission serviced√ +ZMAX trans. treatment
Oil and filter√ +ZMax engine oil treatment
(Was told to clean out the place the filter sits with a baby bottle cleaner technique but I haven't read anywhere how or why this needs to be done so if you know please tell us)

makes sense to clean out old oil I assume. Forgot what guy said at the time.