This topic was bantered about big time over the last few days on MKIV forum. Go to that for a lot of info. What technical facts does 3L base his opinion that for some reason detonation with iridium plug will screw up a car and copper you will not. Detonation will screw up a car period. The answer on MKIV after a lot of back and forth was no one plug, plug #, etc. is the magic bullett for the Supra. It all depends. I have Denso Iridiums and I like them. One objective test that I did read in a turb import type mag was putting Denso Iridiums in a BPU Supra and putting it on a dynojet. The car on the plugs alone generated about 10rwhp more than stock. Nuff Said.
Barry H. 94ttsupra