A friend of mine and I are having a debate whether, or not if you raise your c/r ie;putting ctr pistons in a b18c you should run a colder plug. I say you should, he disagrees, who's right???

 

If you're not detonating with the current plugs, you don't need colder ones. Exackty when you reach that point is not as easy as just relying on static compression numbers, so in essense you're both right and wrong.