I bought some NGK LFR6A-11 plugs online about 6mo ago. I put 12,000 miles on them. THey have had a pretty hard life. I ran extremely rich for about 2 months, and I haven't looked at the plugs yet. I didn't want to buy the plugs online again and looked around the net for an oem equivalent to purchase at local parts store.

Can anyone verify whether or not the NGK LFR6A-11 is equivalent to the iridium STi plug? I thought the LFR6A-11 was copper. I also thought iridium in boosted apps was not ok. But correct if I'm wrong...