A champion bicycle racer, Albert Champion, came to the U.S. in 1899. He got a job with the Stranahan brothers, who had started Champion Spark Plug Company in 1905 or 1906. He was unhappy in his career because he had no control over it. Before leaving Europe, he already had at least one spark plug patent (from 1898). He showed some prototypes to William C. Durant of the Buick Motor Company in 1908. Buick, at that time, was using Rajah spark plugs. The company decided to manufacture spark plugs from Champion’s design in Flint, Michigan, as part of the budding automotive industry, as a cheaper alternative to buying them from Rajah.
Champion began making spark plugs for Buick automobiles. The Stranahan brothers (“Champion Spark Plug Co.”) informed Champion and Durant they could not use the name “Champion” because it was trademarked. The name was changed to reflect Champion’s initials at that time. “AC Spark Plug” was trademarked in 1908. In 1927 AC became a division of General Motors.
General Motors merged AC Spark Plug’s aftersales operation with United Delco in 1974 to streamline its operations and marketing. A variety of AC and Delco-branded products were then marketed by AC-Delco.