NGK

NGK Spark Plugs (now NTK — part of DENSO Corporation since 2024, though still marketed under the NGK brand) is one of the world's two largest spark plug manufacturers, headquartered in Nagoya, Japan. Founded in 1936, NGK supplies original-equipment ignition parts to virtually every major automaker globally — Toyota, Honda, Subaru, Mazda, and many European brands. In North America the company markets under the NGK brand with product lines ranging from standard copper (V-Power) and platinum (G-Power) to the premium Laser Iridium and newer Ruthenium HX series.

The Laser Iridium line is NGK's OE-equivalent aftermarket offering — the same technology NGK supplies to Toyota, Honda, and Subaru dealer parts channels under the respective OEM part numbers. The Ruthenium HX line is a newer introduction featuring a double fine electrode (DFE) design with a ruthenium-alloy center electrode, offering improved ignitability over the iridium platform for applications that demand it.