Why the $17 irridium spark plug in the Rubicon? What is the technical reason?

Thanks in advance.

 

Honda expalined it with two reasons, which neither can be explained in detail without writing a book.

[1] This is the same type plug used in their automobiles that require no service for xxxxmany thousand miles.

[2] The plug is supposed to be the best available plug that does not give all the electricals on the Rubicon fits.

I know it isn't much of any help, but that is just the simple version of the memo Honda sent to their dealers about a year ago.

KNOWSALOT