I don't think anyone said that they would. The topic being discussed was the longevity of the Iridiums and they do last a very long time. I think that comment about 500,000 miles was just a bit of an exageration to make a point.
With all the talk of which spark plug was "better" for this application or for that application, I decided to go out and try them all over a fairly decent amount of mileage on each.
Keep in mind that this was for a Vortech supercharged S2000 used on a daily driven basis through all 4 seasons. I started the S/Cd life with re-gapped OEM platinum plugs and ran those for over 10K KMs, then tried the NGK "racing" V-power plugs for another 6 to 7 thousand KMs, I've had the Densos in there now for many months and maybe a similar amount of KMs have passed. My conclusions are that THERE IS NO DIFFERENCE in terms of day to day "performance" except that the Iridiums don't get as dirty looking over time. There is no difference in the way the car feels in power delivery from one plug to another. The Iridiums, however, tend to be more maintenance free and that's what I want from a daily driven blown car.

 

Like yourself, I have done some extensive experiments with plugs
over the years, and made my own conclusions, which vary little from
yours. I just saw "Iridium" and "SC" in the same thread and a little red
light came on. As mentioned before, a few MR-2 owners have lost
engines after they pinged and broke off a piece of that brittle center
electrode.
Obviously, the Iridiums are a great option in a N/A car, but you may want to visit www.mr2oc.com and do a little reading for yourself.
Just my $.02 worth- Thanks

 

Your input is appreciated and thanks for the caution.
These Iridiums have been in use in supercharged S2000's since the kits first came out some years ago. Although a few engines and drivetrains have been demolished along the way, I don't recall that any of these were attributed to Iridium plugs. I'm sure that the MR-2 people have alarming data on this but I'm going to go by the fact that an MR-2 engine is vastly different than an S2000 engine and the history of these plugs in a blown S2000 will be enough to warrant not worrying about them in my car. I hope I won't live to regret this decision, but buying copper plugs every few thousand KMs is just ludicrous for my daily driver. And the ones for my application are not cheap and they are not easy to obtain.

 

edit by XV,

This kind of comment is counter productive and unwanted. You may think you're being cool by talking gibberish, but I take calling someone a fool to be against forum rules. Learn to speak english and keep this garbage out of UTH.

 

I think it only fair to mention that the only MR-2 engines to detonate were running in excess of 16 psi on the boost, which is very problematic
if the suporting fuel and engine management systems are not in place,
and you are absolutely correct about the two engines being different.
I wish my S2000 made 278 rwhp like my MR-2, but it's not all about power. I still drive the "S" more because it is extremely entertaining.
BTW, I have to change the copper plugs in my MR-2 every 5000 miles,
so I guess I've gotten used to the grind so to speak.
Thanks for hearing me out on the Iridiums!