NGK is an abbreviation for Nippon Gaishi Kaisha or Japan insulator company. NGK was originally established in 1936 with its headquarters in Nagoya, Japan. The company specialises in manufacturing spark plugs and components relating to the internal combustion engine as well as ceramics. The company as of 2007 employed 10,407 people and had a network of 12 sales office, seven liaison offices, two technical centres and 13 production sites. NGK was intentionally founded as a spin-off of their NGK Insulators division. NGK parts are mostly supplied to the local car industry. However, it is still the largest OEM spark plug manufacturer in the world.
NGK parts are popular for two main reasons the first being that Japanese car manufacturers recommend that buyers use NGK spark plugs. The second being that NGK is always innovating and developing better spark plugs and ignition systems for an array of vehicles. So, finding aftermarket parts for even recently introduced vehicles is not impossible. That said NGK is most famous for their glow plugs and spark plugs, in addition to an excellent service life and the use of the best materials which meant plugs last longer and burn fuel more efficiently.