BPR6ES

Let me clarify a little more...


Colder plugs simply have more ceramic material (white part around the electrode) touching the outside housing (metal part with threads) of the plug. The ceramic part is there to insulate the electrode from the casing (which is grounded) and as we are discussing to pull heat from the hot electrode (heatsink affect). Your plugs need to stay at certain temps to stay clean, if they are not hot enough the plugs will build up with carbon (fouling).

So the BPR6ES’s are the same plugs as the BPR7ES except the BRP7ES’s have slightly more ceramic insulating material.


How do colder plug help?

Detonation can be spawned by hot spots in the combustion chamber. If your cylinder temps get really hot your plugs will get hotter, if the insulator does not pull enough heat from the electrode it will become a hotspot that may cause detonation.