Me? NO… But what do I know…I’ve only been playing with Spark Plugs for 33yrs now.
IMHO… Aside from electrode degradation over time (Which may be the factor that allows this longevity with harder more durable electrodes) What limits the time for the Steel Spark plug screwed into an Aluminum Cylinder Head is what happens to the threads over that long of a period of time. Ive seen plugs corrode and actually Bloom or Swell due to corrosion…which severely locks the plug into the cyl head.
Personally I ALWAYS install every single Spark Plug using Anti Seize compound…especially when the heads are Aluminum. I do notice however that I seem to be the only one… Plugs are or seem…to be installed Dry into the heads…regardless of materials used. Now I could be wrong about that but they seem to be installed dry.
I worry about getting plugs OUT of engines mostly… I can attest that a dry Steel plug installed into an Aluminum Head 5-7 YEARS ago will entertain the mechanic unlucky enough to be assigned to change said plugs. I’ve seen VERY ugly things happen when the Un-Initiated mechanic goes about changing these plugs…they usually take all the Aluminum threads with the plug when they simply try to “Run the plugs out” of the head.
Can a spark plug function for 100K miles? Probably …again due to harder more exotic electrode materials… Would I want a plug in my Heads for as long as those miles take to accrue? I think not… Not unless some sort of thread protection was used…and I cant fathom that nothing would be used in this instance to protect or lubricate those threads.
Blackbird