High Performance Spark Plugs

I was just curious if they make anything for the DOHC SL's besides what comes stock. I am really just looking for the best brand to use on my car. Also, the last time the spark plugs were changed was at 60,000 .... i am curious if changing all 6 will free up some nice ponies possibly?

Also, the last time the spark plugs were changed was at 60,000 .... i am curious if changing all 6 will free up some nice ponies possibly?


Well that would depend on how many miles you have now... :biggrin:
It isn't a bad idea to change them if they are overdue. But it wont really bring a noticeable change if they are still in good shape. I honestly don't know what hte best would be for the SL. Stock NGKs are probably plenty fine...I personally would spend money on other things than 'better' brands of plugs. Just my :2cents:

Which is better Iridium or Platinum??

I think Iridium's are better... at least that's what I think. No idea for sure. That's all I buy though.

I think Iridiums lasts longer whereas Platinums are better conductors. However, as stated in other threads, coppers are best but just have to be replaced more often. I think when I redo mine, I'm going with the Platinums. Now I just gotta fine some nice blue plug wires....Kragen maybe? I wanna buy online for cheaper but don't know what the colors will be.... :o/

Copper/Platinum/Iridium arguement is depending on what the needs of your car are. Because of the length of the conductor the resistance is pretty marginal compared to the resistance due to the air gap.
In racing copper is prefered because at the temperature, vibration and pressures you don't want the conductor breaking off.
Platinum and iridium have smaller conductors (because they are harder) which accumulate charge and allow the spark to arc easier (charge accumilates at sharp points).
So if you are talking about everyday driving I would take iridium (lasts longer and I am lazy) but for the money copper is a better buy (platinum is the middle ground).