Quote Originally Posted by SeverAMV View Post
heat range doesnt affect when it will fire, but can cause misfire, the tip is often where the mixture makes a fair bit of contact with when the af mixture enters the cylinder. sparkies at too high a temp for too long can cause preignition and hence detonation, which is why we change to diff temp range in the spark plug, which is also why changing to a lower temp range can fix pinging.

spark plugs have to be of the correct temperature range so they can spread the right amount of heat at the right time to ignite the entire mixture. if the spark is too weak, you'll find that most of the mixture wont ignite as easily, and will ignite later, despite ignition timing.

if this werent true, then why isnt everyone just running the lowest temperature range available?
Not true. Spark strength does not depend on heat. The reason why everyone doesn't run the lowest temperature is because if the spark plug tip is not hot enough, you will get deposits on the tip.