The P6 is a lot like the Novarossi 6C plug. You want to run hot plugs in the .12 engines relative to .21 motors. This is when turbo plugs first started appearing in .12 motors. Now the norm, people are saying to run cold plugs because of these more powerful .12s coming out. They are becoming more and more like .21s, price wise at least.

I generally always use a 6C plug and go to a 7C when the weather gets really hot.