So a compression change should not effect the plug gap spec requirement. I guess what I'm trying to ask since I've installed 21cc dome my compression has increased over stock does the oem gap still apply, or should a different gap be used. Its just a question after reading through this thread, I assumed that plugs come pre gapped, but checked 4 sets I had just now, not a single one was within spec (BR8ES type) from the dealer. Going to double check here on in. Sent from my LG-H831 using Tapatalk