Has anyone installed the Denso Iridium spark plugs and noticed an performance enhancement. I mean they cost like $11 each.

 

I have the NGK Iridiums in my car. I got them off ebay for $25/set. I only run them because they came one heat range colder, they were cheap, and I am running forced induction. If you aren't boosted or spraying, there is no need to deviate from the Honda recommended stock NGKs. And plus, there was no performance increase, just a smoother idle from the crappy Denso platinums.

 

iridium plugs were created for one purpose: less maintanence for the average joe.

If you're looking for performance, copper is the best conductor and will out perform any other type (platinum, iridium), but they don't last as long and will need to be replaced sooner. Copper plugs are dirt cheap, though, compared to iridiums and platinums.

I change my NGK coppers every second oil change. I could probably go 4 oil changes before changing them, but i track my car regularly.

 

So for normal driving are NGK Platinum spark plugs a good replacment from the oem ones?

 

If your car doesn't require platinum, just get the normal stock recommended plug. There is little to no difference between the two, performance-wise.

 

I have question.I have B16A engine with intake,header,exhaust,msd sci ignition,cranecams ps91 coil,spoon sport sparkplug cable. My question is for performance wise,which one is better, using denso iridium ik20 or the stock NGK spark plug? Is it make a big difference between these two,performance wise?

 

maybe you guys should read my post again....
performance wise; copper is the best, at the cost of longetivity
copper is the best conductor.

but if it's brand you're comparing, then i wouldn't know. You're probably wasting
your time trying to find the best performing brand only to gain 1-2hp.