huge difference how? In terms of performance? I doubt it.
In terms of construction? Same basic design (two electrodes) different alloys. In terms of lifespan, I would bet on it. Irridium is a harder alloy and should not decay as fast.

However, spark plugs are like toothbrushes, wait a few months and a newer more "revolutionary" one will come out.

Cool, again thanks for the advice.

Id say just get the ones that last longest. And fyi, Iridium its own metal its not an alloy. Alloy is a mixture of 2 metals to get desirable properties, Like stainless steel is 10% chromium and the rest steel. And silver would idealy be the best spark plug, Because it is the best conductor. But im guessing it wouldnt last too long inside a motor.

Im well aware of the fact that Iridium itself is an element not an alloy, but I was under the impression the NGK Iridiums were not pure elemental iridium in the electrode. My understanding of Iridium is that it is very dense, and hard but its also extremely brittle, therefore NGK uses Iridium in an alloy to reduce brittleness and make the electrodes easier to manufacture.

but I guess when I wrote that sentence, I should have just said "metal" instead of "alloy", but I didnt know the resident fact checker would call me out on it. :x:

Haha, i didnt mean to make it sound like that, so sorry. Just wanted to say it, because a lot of people confuse "metal" with "alloy", even big companies for the most part. The other thing is, Im sure the plugs are made of iridium, But its not exactly what id want to have a spark plug made out of. The best conductors are silver, copper, and gold, in that order. Even nickle or something would be better. I know people trust them but i think the iridium thing is just a marketing ploy.

Its cool, Im human too it seems.

as for the topic:
Well there are other things important in the construction and function of a spark plug that are just as, if not more, important than conductivity. Things such as heat dissapation, heat resistance (melting point), erosion and oxidation. Its also not just about the materials used but how they are used together and the design and shape of the plug. These properties affect the way the mixture is ignited, the longevity of the plug, cylinder temperatures, and a variety of other variables that while I admit are nominal differences, are indeed what separates the good from the not as good. Its like cables and wires to audiophiles...do the expensive ones make a difference? To the audiophile they do.
Its like you said, if the only thing to worry about was conductivity then we would have plugs made of silver. But its also like I said, wait a few months something new will come out.

Iridium is an element. It is here because the meteor that was said to have killed the dinosaur's was made of iridium. It formed the gulf of mexico a few million years ago. There is a layer of iridium about an inch or less covering the earth that was caused by that meteor. Probably the best metal that exists on the planet. Probably not the best metal for spark plugs though. Stick with NGK. They are the best bang for the buck. All it is, like most already said, is the electric signal traveling through the least resistance. The gap provides just enough for the electricity to travel through the free space to reach the other metal to continue the charge. But, so much energy is lost in the gap that the charge is basically done when it reaches the other electrode so the charge ends at the gap. All you need is one electrode, one with good conduction, which ngk provides. Spark plugs don't do much besides conduct electricity. Clean plugs, gapped correctly are fine. Worry more about air and fuel flow, that is where the power gain is at. I believe the injectors are capable of a lot more flow then stock; get a chip to balance air and fuel flow to get the best power. Change plugs about every 15K and you'll be fine.

and i'm out.

LOL, and now a word from the resident geologist...hahaha

first of all...we were talking about NGK Iridium plugs, secondly changing plugs every 15k on a good running engine is a waste of money. and thirdly no one was debating the fact that adding fuel/air, etc yields more power...the discussion was about spark plugs and which ones are better...but I see that some people just want to steer the topic elsewhere so.....

:whateva:

I can feel the love.

well stop feeling THAT "love" and go do something productive you dirty boy!