Quote:
Originally Posted by curtisr
I was surprised to learn that one of the most significant differences in spark plugs was its ability (speed?) with which it transfers heat from the combustion chamber to the engine head. So what's best for our 924s? This:
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as adding a turbo or supercharger, increasing compression, timing changes, use of alternate fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature, necessitating a colder plug.
Source: https://www.ngk.com/learning-center/article/207/what-is-a-spark-plugs-heat-range |
Not only that, the addition of Ethanol to gas and the effect on spark plugs was also addressed in a TSB by NGK.
