OK, I’m game. Whunter wrote a sticky entitled “Danger: RESISTOR SPARK PLUGS” in which the recommendation is to stay away from resistor spark plugs. Some discussion began and it was requested that further discussion continue in a new thread – so here we are. There has been a lot of emotion over whether resistor spark plugs are applicable to Mercedes, et. al. Opinion is sharply divided. This thread will explore people’s viewpoint.
I actually broached this question a couple years ago in another MB website and was ceremoniously crapped on. At the time, Bosch had just released their Platinium+4 product line:
http://jobs.boschusa.com/AutoParts/SparkPlugs/PlatinumPlus4/
…and I was interested in others views/opinions.
The ‘compelling’ argument against resistor plugs has always been one centered on this logic: MB Engineers chose Bosch non-resistor plugs… MB Engineers are smarter than us… so Bosch non-resistor plugs must be the *only* plug that will work, otherwise the MB Engineers would have chosen something different or given us options. There are other arguments, but this one seems to always boil to the surface.
This logic is unadulterated bull. Bosch non-resistor plugs are good quality plugs – no question – but they are also the least expensive for any auto manufacturer to use. The savings per automobile adds up pretty quick, as opposed to relatively more exotic, resistor plugs. MB Engineers do *not* engineer around a spark plug; they simply use a spark plug that is inexpensive to the manufacturing process. In other words, MB Engineers have other things to worry about than a simple US$0.50 (that’s 50-cents) per unit part bought in bulk through inter-company purchase agreements. My professional background as an Engineering Manager to a manufacturing company provides me a unique opportunity to understand the ‘drive’ of companies to save pennies in this manner.
I believe the use of Bosch non-resistor plugs is driven more by bottom-line profits than electrical engineering excellence. I welcome objective data that supports the claim that only non-resistor plugs are to be used in Mercedes motorcars. Folks claim to have read MB documentation that clearly indicates *only* non-resistor plugs are to be used. But as of this writing, no one seems able or willing to produce the objective information. Lots of theory… lots of ‘history’… lots of emotion… very little objective data.
I have run resistor plugs in various Mercedes over the years and seem to have had suffered no ill effects that can be attributed to resistor spark plugs. Performance differences have been, unfortunately, subjective. Thus, I do not profess to know one-way or another. But I am always interested in reviewing objective data. This thread is to address the question of whether resistor plugs (of any brand) can safely be used.
So, what do you think of the subject?