Est. 1954
Heritage & History
STP — Scientifically Treated Petroleum — was founded in Chicago, Illinois in 1954, developing the oil treatment formula that Andy Granatelli would make famous through his association with Indianapolis 500 racing. The racing connection gave STP a credibility in American automotive culture that translated into commercial success far beyond the racing market. By the 1960s, STP Oil Treatment was a ubiquitous presence in American service stations and filling the trunk of the typical American car owner.
The Chicago formulation heritage continues today through a product line that covers oil treatments, fuel injector cleaners, gas treatments, and diesel fuel additives. STP's longevity in the automotive additive category reflects the continued demand for products that address the real-world challenges of maintaining older American vehicles — fuel system deposits, engine sludge, and the combustion inefficiency that accumulates in engines that don't receive regular professional service.
Formulated in the USA
STP formulates its automotive additives at US manufacturing facilities, with the Chicago headquarters overseeing product development and quality standards. The oil treatment formula uses viscosity improvers and anti-wear additives that reduce metal-to-metal contact at startup — the operating condition where engine wear is most concentrated because the oil film has drained away from bearing surfaces.
The fuel injector cleaner products use detergent chemistries that dissolve the varnish and carbon deposits that accumulate on injector tips and intake valves over time. The effectiveness of these products is measurable by before-and-after fuel economy and power tests — the kind of practical validation that has sustained STP's reputation across generations of American car owners.
What Sets Them Apart
STP's advantage is the combination of a 70-year track record and formulations tested against the specific conditions of American vehicles, American fuel standards, and American climate ranges. Products developed for European markets or generic international formulations don't necessarily perform optimally in American conditions — the ethanol content of American gasoline, the wide temperature ranges of continental climates, and the age profile of American vehicles create specific demands that STP has addressed through decades of domestic formulation work.
For buyers maintaining older vehicles with 100,000+ miles, the STP High Mileage Oil Treatment addresses the seal and gasket condition that determines whether an aging engine loses oil between changes. This is a product category with genuine utility for the large portion of American vehicles that are more than a decade old.
Frequently Asked Questions
Is STP made in the USA?
Yes. STP manufactures 6 verified products in Multiple US facilities. STP has formulated automotive fuel and oil additives in Chicago, Illinois since 1954, becoming one of the most recognized names in American automotive maintenance chemistry with a presence in virtually every auto parts store in the country.
Where is STP manufactured?
STP is headquartered in Chicago, IL. Manufacturing takes place in Multiple US facilities.
What STP products can I buy?
We carry 6 verified STP products across Automotive. Every listing links directly to Amazon with verified American manufacturing.
When was STP founded?
STP was founded in 1954. STP has formulated automotive fuel and oil additives in Chicago, Illinois since 1954, becoming one of the most recognized names in American automotive maintenance chemistry with a presence in virtually every auto parts store in the country.