My “doesn’t care” came from the tech rep verbally. He was answering that any resistance is ok because it’s not broken. Of course tempest gives a different answer. I treat champion like the tempest. Yes I have had bad champion but rare. I will go through my pile of spares if I find one way out, to match out a used set. Depends on need. A friend’s shop gave up on them. His volume was way more than mine. He didn’t change every plug that came through the door, but if there was ignition problems , the tempest went in.