Got lar....its somewhere in global denso website comparing Power IK20 vs OEM iridium by Denso. Cannot find link coz I browse here and there ones, don't know where it goes.
Anway got this from Myvi forum again somewhere...
Reply from Denso Japan....
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"We suggest recommended Iridium Power life span is around 30000km.
This longer life time is derived from world smallest 0.4mm Iridium electrode.
The finer electrode diameter, the smaller required voltage. If the required voltage is
smaller, spark plug can last longer.
The Iridium Power life span 30000km does not mean just after 30000km, Iridium Power dies.
If you still feel good engine condition,
you may continue to use our Iridium Power.
Is DENSO Iridium Power now famous in Malaysia?"
So 30K optimum, 40K max. Also read if life span is 30K, its best to change b4 the max life span coz when misfiring, etc start occuring more frequently, your fc and power degradition not worth the extension. However if car still save FC (PE save FC?????) and still same power....like above mentioned, up to us to judge.
Bro, not that dun believe but what you said you never provide any link or drillz.
Somemore, Myvi forum.
From global denso too, the service life never mentioned is Iridium Power.
Guys, which brand of engine oil you all using? any good recommend?
Say NO to Shell.