"Indexing" and replacing Jazz sparkplugs

[claymore]

.....

[Dxs]

you can often just use coppers instead of iridums. I have heard of quite a few people with high tuned nissan turbo engines using coppers instead of iridums and just replacing them more often.


Maybe just leave the iridiums in for longer and just clean them etc? But do they have a crush washer design? that would be concerning..