dieselenthusiast wrote:
tommudd wrote:
100,000 ?
I've never trusted a spark plug that long
Guess I just like to swap things out more than normal

If I were running a standard plug, then I would want to change them at 40,000 mile intervals. I pulled the OE plugs around 25,000 miles and they looked good. The Iridium can handle heat better and do not corrode or get the electrical wear as quickly as the standard plugs. Plus, “the center electrode of Iridium IX spark plugs has an extra anti-fouling mechanism. A thermo edge between the center electrode and the insulator nose provides a gap for a secondary micro-discharge to jump and initiate a self-cleaning process.” I agree that 100,000 miles is taking plugs to an extreme mileage, especially for how cheap they are to replace. But I think the Iridiums could last that long in good working condition. I guess I will find out, lol. Heck, there are people on this forum who haven't replaced their stock spark plugs with over 80,000 miles on their KJ.

If they they are set at the gap I think they are about 30k-40k and they will be done,either that or the coils will be.
Just remember our ignition system is designed for copper plugs and switching to platinum or iridium changes the resistance in the system.To low of resistance(not copper core plugs) will cause a very high voltage spark which will erode at a higher rate,not good for the coils either.
If you want to run platinum plugs the gap needs to be set at about 0.060" and 0.080" for iridiums to be about the same resistance as copper core plugs gapped at 0.040".