xviper

Just did a search and a few interesting things came up but nothing that answers this question. It seems Honda put both NGK and Denso plugs in this car. Some say the NGK's are platinum but some say neither is. Somebody said that the stock plugs looked like sh$t when they pulled them out. I pulled one of mine out a couple of weeks ago (near 20,000 km) and they looked quite normal. Since the Helm manual says the plugs can stay in for 105K miles or 7 years, nobody is even close to this yet. If they are not platinum, then how is it that they can last so long? Can we trust Honda to be right on this? It's not like "normal" plugs are that expensive to replace every year or two (or would this just be a useless waste of time?).

cdelena

Modern platinum plugs (as all standard S2000 plugs) are designed to meet emission standards for 100K miles, and performance will be adequate, but maybe not as good as others. High performance plugs using copper, gold, and different alloys have much less resistance and can have a bigger hotter spark, but must be replaced much more often. The recent introduction of iridium plugs gives a compromise of the hotter spark from lower resistance, and a long enough life to pass emission requirements (they are standard on several ULEV

xviper

So what you're saying is that the S2000 plugs are platinum? That would explain a lot. If we didn't mind changing the plugs at frequent intervals, can we use regular copper type plugs to gain higher performance?

cdelena

[QUOTE]Originally posted by xviper
[B]So what you're saying is that the S2000 plugs are platinum?

twohoos

Thanks for the reminder cdelena - getting about time to order new IK24s (9K on mine)...

And just to echo: the stock plugs on my '00 were definitely Denso platinums (PK22 as I recall - and they were torqued correctly! ).