spark plug gap

I know this an old post but. What does changing the Gap  do exactly? Do the plugs burn hotter with a larger gap or cooler? So if half of my plugs are white and half are dark brown can I adjust the gap to make them the same?

The Spark-Plug Gap

One of the key factors that make a spark plug work well, or not, is the size of the gap between the electrodes. If the gap is too small, the spark will likely be too weak and cause the engine to run poorly or with poor efficiency.

if the spark plug gap is too large, the spark is unlikely to consistently "jump" across the long distance between electrodes, thus leading to a rough-running engine or one that doesn't run at all.

https://www.newgateschool.org/blog/entry/what-you-should-know-about-spark-plugs-their-adjustment-and-their-replaceme#:~:text=The%20Spark%2DPlug%20Gap,poorly%20or%20with%20poor%20efficiency.

The size of the Gap has nothing to do with the temperature the plug experiences.

Plug temperatures have to do with the heatsinking abilities of the plug body.

Hoter plugs will project farther out onto the cylinder and have longer electrodes that also therefor have longer heat sink paths.

Cooler plugs will have the reverse.

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The smaller the plug Gap, the easier it is for the the spark to jump the gap at lower voltages.

A plug that sparks easily in air might NOT spark at all when subjected to heavy hydrocarbon vapors compressed to 10 atmospheres.

A 0.025"gap will spark at less than 1000v in room air but may need more than 20,000v when in the compressed cylinder.

If the gap is too large, you risk a misfire due to insufficient voltage to bridge the gap.

If the gap is too small, the combustion byproducts will soon bridge the gap and again No Spark.

The Temperature of the spark has little effect on the combustion, As long as it lights the fire on schedule, that is all it needs to do.

Consider a forest fire that is consuming 100 acres an hour, does it really matter if it was started with a massive lightening bolt or a discarded cigarette???