This time a short post, which is dedicated to the “antivaxers” of the spare parts. Or for persons who claim that the “original parts are the same, which could be bought in OEM boxes”, “BMW only charges a lot of money”, etc.
As an example – spark plugs. At a free moment, I overlooked the images of the spark plugs stored in my phone.
Here, in the image:
a. new spark plug: BMW Champion; purchased from the BMW dealer;
b. slightly used Champion spark plug, take off the B58 engine. Model of the spark plug: as if 100% analog, intended for the current engine.
Here, the image with the installed spark plug:
And here, the code of the installed spark plug:
Conclusion: the engine has the Champion spark plugs, intended for it, installed!
What differences do we see?
a. insulator – longer for the BMW spark plug, it has rounded profile;
b. central electrode: thicker for the BMW spark plug;
c. most significant visual difference – the side electrode of the BMW spark plug is more advanced.
Here, the image of the BMW sparks plugs in high resolution:
In the image, you can clearly see that the “end” of the side electrode had a “strange” shape. It looks like someone has soldered it… This time – not soldered, but welded/melted! In the place where the spark is created, a piece of another type of metal is fused! Why is such depravity necessary?
The spark is an ark discharge process, which happens at a temperature of several thousand degrees. In such high temperatures, even the most durable metals are evaporating. In addition, the additional “disintegration” is promoted by the high electron flow, which flows via electrodes air gap every time.
That’s why it is so important, from what kind of material is used to manufacture the spark plug electrodes. Here is the answer, why these spark plugs are so expensive, around EUR 27. The electrodes of the spark plug are made of Iridium (and/or Platinum).
If all metal parts of the spark plug were created from these special metals, it would cost like a good BMW. That’s why only the contact surfaces are made of Iridium/Platinum. But the most important – BOTH electrodes of BMW Champion spark plug are “special”, at the same time for the “regular” Champion – only the central electrode has this feature. The side electrode is without any special alloy.
Short info, what is this special material – Iridium. Wikipedia (C)
Iridium is a hard, fragile metal of platinum group and is very rare in nature, mostly as an impurity of platinum nuggets. In relatively large amounts, it could be found in meteorites. Iridium is used for heat-resistant alloys; it has excellent corrosion resistance.
Iridium is one of the rarest elements in the Earth’s crust. Its concentration is approximately one part of a billion, which is much less than the concentration of gold or platinum.
In 2010, the price of iridium was 642.15 US dollars for a Trojan ounce.
640 USD for 31 gram or 20.000 USD/kg. Not a cheap metal!
And here is the image of the official Denso group webpage:
Previously mentioned Champion spark plugs are a good example:
BMW spark plug corresponds to the Vehicles manufacturer example, but the “simple” Champion – to the Iridium Power example. Differences?
a. central electrode – “weaker”;
b. side electrode – simple, pressed vs Platinum.
What is Platinum? Wikipedia (C)
Platinum is a dense, elastic, and corrosion-resistant grey-white transition metal. In nature, Platinum basically is a free-occurring metal, although it is scarce in the Earth’s crust. Platinum is an expensive metal, approximately 2 to 3 times more expensive than gold.
So – the price of Platinum is around 100 .. 150.000 EUR/kg! Here is the explanation, why only a tiny piece of Platinum is used in the spark plug, not all side electrode of the spark plug is made of it.
Conclusion: these are the spark plugs of COMPLETELY different levels! Although the price is similar: 27 EUR vs 10 .. 17 EUR
Is anyone still ready to argue that BMW Champion = Champion, only “in a different box”?