Spark Plug Technical Information



Spark Plug Characteristics


Revolutionary 360 Degree Laser Weld

To provide the best plug in the market, DENSO developed a proprietary 360-degree laser welding process : the result is the highest quality bond that ensures structural support for the Iridium center electrode, which resists wear and oxidation, even in the harshest combustion environments.

Understanding Heat Range

The heat range of a spark plug primarily depends on the length of the insulator nose. The heat from the combustion is transferred from the insulator nose, through the centre electrode, to the plug housing and then to the cylinder head and the engine cooling system.

The challenge of spark plug design is to find the proper balance between the engine speed and the plug temperature. This is required to ensure oil or carbon fouling doesn't occur at low engine RPMs, or pre-ignition at high engine RPMs or Heavy Duty applications.

Choosing the correct heat range is very important. Standard vehicles should use the heat range specified by the manufacturer. If your vehicle is not running at standard specifications you may need to change to a spark plug with a different heat range.

Spark plug temperatures must remain between 450°C - 900°C. Cooler temperatures won't allow the plug to self-clean by burning off carbon or oil deposits. This will lead to misfiring and poor acceleration. Hotter temperatures will cause overheating of the plug resulting in power loss, detonation, pre-ignition and possible engine damage.