The denso iridiums that they recommend for honda is IK16/20/22. This plug is not the 'projected/extended tip' type plug like the stock NGK (ZFR5-11) and Denso (KJ16..) plugs. If you hold the two plugs side by side and observe the distance from the seat to the ground electrode you will notice that the iridium is visibly shorter by a good margin!! Duh! Obviously because its not an "extened projected tip" type of plug!!

What is this extended projected tip ? How important is it to follow this requirement ?
If it is important (which I believe it should be) then how can they recommend this plug to be suitable in a honda motor even though it does not meet the oem spec ??!!

This is the second time I have had a not-so-great experience with denso plugs when it comes to specifying things clearly and accurately - https://honda-tech.com/zerothread?id=1683454

 

..er..bad question ??