There sure is a lot of talk about how Iridum spark plugs need lesser voltage, improve fuel efficiency (up to 3%!!!!), last longer, give more horsepower, better acceleration, etc., but is any of this true?
Split-fires were supposed to do all this and more, I never noticed much difference :(
The one thing that I am prone to believe is the longevity issue but then I can't find any recommendations for extended change intervals which makes me doubt the whole Iridium thing as mostly hype.
My Subie with NGK regulars is due for new spark plugs. Any suggestions would be greatly appreciated.
MN