Hot Spark Plugs Vs Cold Spark Plugs

A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of an SI engine or Petrol engine to ignite the compressed fuel/air mixture by an electric spark.

Based on Heat Range it is of two types: Hot type spark plug & Cold type spark plug.

A spark plug is said to be “hot” if it is a better heat insulator, keeping more heat in the tip of the spark plug. A spark plug is said to be “cold” if it can conduct more heat out of the spark plug tip and lower the tip’s temperature. Whether a spark plug is “hot” or “cold” is known as the heat range of the spark plug. The heat range of a spark plug is typically specified as a number.

In a spark plug, the metal shell of each fitting works at a nearly indistinguishable temperature from the metal of the head itself. Plugs with the same diameter will still have different lengths of the insulator nose. This means, they each can indicate which one is hotter and which one is cooler. In most cases, spark plugs are made with various warmth ratings, from extremely cool to exceptionally hot, so an alluring attachment can be found for your motor. This is, of course, contingent upon what you require, such as your riding or driving conditions.

The warmth scope of a spark plug varies. It has A-One-moment-impact in the burning chamber of the internal combustion engine and general motor temperature. A chilly fitting won’t tangibly chill off a motor’s running temperature. A hot spark plug takes a few minutes to return to its normal temperature. In this temperature, plugs have a big role as both spark plugs are dependent on temperature.

Difference between Hot Plugs and Cold Plugs

Hot Plugs

• Have a long Insulator nose.
• A great surface area exposed to the hot combustion gases.
• Heat transfer to the engine head is slower.
• Its firing end heats up quickly.

Cold plugs

• Have a short Insulator nose.
• A less surface area exposed to the hot combustion gases.
• Heat transfer to the engine head is quicker.
• Its firing end does not heat up quickly.

So, these are the main difference between both spark plugs. Hence it is always advisable to use spark plug based on their Heat Range that matches a specific engine and its condition of use.