Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. ACDelco is an American automotive parts company. Over its long history it has been known by various names such as United Motors Corporation, United Motors Service, United Delco, merged with AC Spark Plug and known as AC-Delco. United Motors Corporation was formed by William C. Durant in 1916 as an automotive component and accessory holding company. Durant was the owner of Buick and founder of General Motors in 1908.