I've encountered original plugs within the change interval that were very difficult to get out. Therefore, I use never-seize on any plug I install. I experimented over the years with how much. I've had a couple instances where I just put on a very little bit and then had the plug difficult to remove later. So I make sure to thoroughly coat the threads. But I reduce the torque by 25%. Never had a problem and never stripped a thread so far.