Spark plug having enhanced capability to ignite air-fuel...

Spark plug having ground electrode and intermediate...

Spark plug having ground electrode having cross section with...

Spark plug having ground electrode including precious metal...

Spark plug having ground electrode made of NI alloy and...

Spark plug having heat- and corrosion-resistant surface

Spark plug having horizontal discharge

Spark plug having horizontal discharge gap

Spark plug having improved configuration of ground electrode...

Spark plug having improved consumption resistance

Spark plug having insulating oil

Spark plug having intermediate electrode and non-parallel series

Spark plug having iridium containing noble metal chip attached v

Spark plug having iridum alloy tip, iron-based alloy tip...

Spark plug having noble metal tip

Spark plug having noble metal tip

Spark plug having resistance against smoldering, long...

Spark plug having ring shaped auxiliary electrode with thickened

Spark plug having spark portion provided with a base...

Spark plug having specific configuration of center electrode...