well, some of us are either out of warranty, can't see how the dealer is going to void anything based on a non-oem spark plug, or have more serious mods a dealer is going to whine about before the plugs.

if the JCW plug manufacturer itself says you can get better performance from a single electrode plug, why not do that if you care about peformance? if you just want the long life them so be it, but if you've already sprung for a JCW, performance must be a concern. how much fear is being induced here by a "non standard" plug?

 

Well, for me quiet a bit after hearing of plugs blowing out of heads. Not something I want based on saving a few bucks.
But to each their own.

 

My experience showed a better running car with the OEM JCW plugs over both the Denso and NGK iridiums. Do you have anything besides this correspondence with someone from NGK? And who exactly did you talk to?