STP is an American brand and trade name for the automotive additives, lubricants and performance division of Armored AutoGroup.
Founded in 1953 in Saint Joseph

Saint Joseph, Missouri

Saint Joseph is the second largest city in northwest Missouri, only second to Kansas City in size, serving as the county seat for Buchanan County. As of the 2010 census, Saint Joseph had a total population of 76,780, making it the eighth largest city in the state. The St...

, Missouri, the company’s name, STP, was derived from “Scientifically Treated Petroleum”. The company entered into the marketplace with one product, STP Oil Treatment.

In 1961, the company was acquired by the Studebaker-Packard Corporation

Studebaker-Packard Corporation

The Studebaker-Packard Corporation was the entity created by the purchase of the Studebaker Corporation of South Bend, Indiana, by the Packard Motor Car Company of Detroit, Michigan, in 1954.Packard acquired Studebaker in the transaction...

. Studebaker briefly tied STP into its advertising as an abbreviation for “Studebaker Tested Products”.