On the other hand...
RE expert Tim Busby from NZ claims that a projected tip plug is better... improves burn or something.
I've been running an irridium NGK BPR8EIX ("P" is for projected tip) in my '07 iron-lung for a couple of years. Plug is about 1/8 inch longer. No problems with fouling on the plug tip, but don't really notice any change in idle or performance, either. Overall, probably not worth the cost, but hasn't hurt anything.
Is a plug thread more fun than an oil thread?
Mike and Stumpy in Michigan