Although phosphorus is no longer used in gasoline, it (and zinc, another low-level catalyst contaminant) was widely used in engine oil antiwear additives such as zinc dithiophosphate (ZDDP). Beginning in 2004, a limit of phosphorus concentration in engine oils was adopted in the API SM and ILSAC GF-4 specifications. Although catalytic converters are most commonly applied to exhaust systems in automobiles, they are also used on electrical generators, forklifts, mining equipment, trucks, buses, locomotives, motorcycles, and on ships. They are even used on some wood stoves to control emissions.[5] This is usually in response to government regulation, either through environmental regulation or through health and safety regulations. Custom setups, especially for vehicles that do a lot of off-roading are also available.

From the inception of the small block Cobra, Carroll Shelby intended to build a race version of his lightweight roadster