I just bought some ngk iridiums, and the guy told me they didn't need to be gapped. Is this right? If not, what should the gap be?
You can't gap them. They are pregapped, and the electrode is pretty fragile and can break quite easily.
You should always check the gap on any plug before you install it. I have seen plugs that have been so far out that it would have been a crime to install them. Yes plugs come pre gapped but for what car? who checked them to make sure they are right? Did somebody drop the box or the plug? Better safe than sorry
Subaru says: .028 - .031 inches We run ours .030 Depends on your set up. If you are within this spec. you should be fine. If the plugs are not correct.................. be very very careful trying to correct them. Do your best not to touch the center electrode when moving the ground electrode. They are prone to breaking easily. Hope that helps.
