Selection of spark plugs

The selection of a spark plug can determine its calorific value based on the engine's compression ratio, speed, and air fuel ratio.
The calorific value of commercially available spark plugs ranges from 5 to 13. The larger the value, the colder the spark plug, which is known as a cold type. High compression ratio engines require the use of cold type spark plugs. The smaller the value, the hotter the spark plug, which is a hot type. Low compression ratio engines require the use of hot type spark plugs.
The production of colder spark plugs is more sophisticated than ordinary products, so it can ensure the accuracy and quality of ignition during high engine RPM, thereby ensuring maximum power at the limit of the engine. In addition, its resistance is also controlled very small, and the number of trips is not lost due to the increase in speed. So using spark plugs with higher values is beneficial for habitually increasing engine speed.