Denso spark plugs have been a major player in the Japanese auto industry since the 1940s and their performance spark plugs have been a favorite choice of American import and racing enthusiasts for decades. The Japanese performance spark plug company was founded in 1949 and made their splash in the American auto world as an OE manufacturer in the 1960s. Denso has had success as both an OE manufacturer as well as an aftermarket parts developer. The company has earned awards in both categories, including the PACE award from Automotive News and General Motors' "Supplier of the Year" award.
While there's no denying the quality of Denso's OE parts, it's the company's line of spark plugs that won the hearts of American performance junkies. Denso first introduced its patented U-Groove design in the 1970s, and their plugs are now an industry standard. Before the U-Groove, conventional plugs could only be improved by increasing the spark gap, which lead to misfiring at high speeds. For Denso, the problem wasn't the size of the gap, it was the size of flame. With that in mind, Denso created a deep groove on each of their spark plugs to protect the flame and let it grow. The innovation proved to be nothing short of revolutionary, and the Denso Spark Plug became an industry leader over night.
Denso continues to innovate to this day with the Denso Iridium Power Spark Plug and the Denso Long-Lasting Spark Plug. Instead of unitizing the conventional platinum construction of other plugs, Denso Spark Plugs are made of iridium, a corrosive-proof metal that can trace its origins to a 50 million-year old asteroid and is widely considered one of the rarer metals in the earth's crust. Each of these plugs designs has been dyno-tested for serious performance gains and designed to withstand 4,000 degree temperatures for a long service life.
Denso operates 25 manufacturing companies in North America, including multiple plants in the United States. Denso's North American Headquarters are in Southfield, Michigan.