As you know:

• In the United States alone, there are 500 million dollars worth of Spark Plug's sold each year in after market sales.
• In the United States, 70% of car owners change the spark plugs on their own.
• The spark plugs are replaced every time the vehicle requires a tune-up.
• Spark Plug manufacturers sell the "After Sales" spark plugs through Spark Plugs printed on CD's, or on-line catalogs via Internet. In these catalogs they recommend (in the "application tables" section) only one type of spark plug (standard, platinum or another variety, but with only one Heat Range specification) according to the vehicle brand, model, year and engine.
• Every time, when tuning up the vehicle, the person replacing the spark plugs must first observe the conditions and color of the carbon deposits at the extreme of the sparkplug, which is in contact with the Combustion chamber.
• Several times, according to the condition and color of these deposits, the Spark Plug Condition Chart will show: "Plug heat range too cold or too hot". This occurs because of different driving conditions and/or engine conditions, different climates, gasoline quality, and also sport modifications. This is even more applicable when sport modifications have been done to the engine. For all of these reasons the vehicle might need a sparkplug of different Thermal Range than recommended by the catalog.
• However spark plug catalogs do not indicate anything of what the user should do if these conditions appear, nor do they indicate which sparkplugs could be the alternative for each of these different conditions of the vehicle and its variables. This is because they can not.
• So therefore, the person who installs the spark plugs is not even aware that the problem exists. There is also a lack of guidelines to solve it, for the catalogs do not suggest the right spark plugs with the correct thermal range, in relation to the particular conditions of its vehicle.
• The Heat Range of the spark plugs is not visible. It is only indicated by "sales symbols" which are composed by alpha-numeric components which do not show the Thermal Range, and also include other characteristics of each spark plug.
• Each spark plug manufacturer has created their own "sales symbols", which are not standardized and are very problematic and confusing even for professional mechanics, much less the general population.
• When these conditions appear, the customer wants to purchase the correct spark plug, which needs a different heat range, but does not know how to choose it.
• Then the customers asks:
  • What is the Heat Range of this spark plug?
  • How do I do to determine with precision the Heat Range of the spark plug in my vehicle under its conditions?