Andy Granatelli, of auto racing...

...fame, died at age 90. From his obit in the Times (my emphasis):

In 1961, the Studebaker Packard Corporation acquired Chemical Compounds, a company with seven employees and only one product: STP (for scientifically treated petroleum). Mr. Granatelli was named the president and changed the company name to STP.

Within a decade, the company had 2,000 employees and was selling more than 100 million cans a year, and its annual sales of $2 million had grown to $100 million. STP decals, with the slogan “The Racer’s Edge,” were everywhere, both at racetracks and on the bumpers of family station wagons. Mr. Granatelli appeared in commercials for the product.

But in 1971, an article in Consumer Reports said STP oil treatment was actually “thick goo,” a worthless oil thickener. Mr. Granatelli denied that, but stock trading halted, and in two days, the stock, which had been at $58, fell to $38.

In 1974, STP was sold to Esmark Corporation for $135 million.

If you grew up as I did in the late 1960s and early '70s, you can attest to how ubiquitous the STP brand was. It's true: those decals were "everywhere." And it seemed that even though everyone had their own pet theory for what STP stood for (both serious and otherwise), almost no one knew it was really "scientifically treated petroleum."