In the easiest to understand article I've read about octane, knock, pinging, and in the process the author gives you a understanding of how it was all profit driven over the basic interests of the health of all humankind.
" ...one decisive drawback, however, which was its tendency to cause harmful deposits in human blood, bones, and brains. Lead poisoning had long been known to cause such alarming maladies as spasms, hallucinations, seizures, blindness, kidney failure, brain damage, madness, coma, and death. "
" To manufacture and market their incredible new engine-enhancing additive– which had been dubbed Ethyl– General Motors partnered with Standard Oil and Du Pont to form the Ethyl Gasoline Corporation.
Consumers showed interest, particularly after the Indianapolis 500 motorcar race on Memorial Day 1923, where the first, second, and third-place cars were all fueled by Ethyl gasoline. After that, the fortified fuel enjoyed rapid widespread adoption, and indeed it lived up to its mechanical claims. In a note to Kettering, Midgley estimated that Ethyl would eventually be adopted by at least 20% of the nation's fuel supply, providing an annual gross profit of about $36 million. "
" ... results showed that airborne lead had been negligible before 1923, and that it had climbed precipitously ever since. In 1965, when the tests were conducted, lead levels were roughly 1,000 times higher than they had been in the pre-Ethyl era.
He also compared modern bone samples to that of older human remains, and found that modern humans' lead levels were hundreds of times higher. "
" The Ethyl corporation had powerful friends, including a Supreme Court justice, members of the US Public Health Service, and the mighty American Petroleum Institute. Nevertheless, Patterson was unrelenting, and the resulting rise in scientific and public awareness eventually led to the Clean Air Act of 1970, and a staged phaseout of leaded gasoline.
Ethyl and Du Pont sued the Environmental Protection Agency, claiming that "actual harm" must be demonstrated rather than just "significant risk," an effort which successfully prolonged lead additives' life by another decade.
By 1986, Ethyl and its ilk were virtually eliminated in the United States, and Americans' blood-borne lead levels have since dropped by 78%. "
" Some historians have argued that Midgley's tetra-ethyl lead was a necessary evil; one which hastened the progress of efficient engines, thereby advancing the economy and contributing to victory in World War II.
It is worth noting, however, that in the early years of Ethyl's availability, basic refinery advances boosted the base octane of fuel by 20-30 points, whereas Ethyl additive only boosted it by about nine points.
In retrospect, Ethyl's octane improvements were somewhat overstated, and the product owed most of its success to crafty marketing, misleading research, and chronic government incompetence. Whatever Ethyl's benefits, it saturated the planet with an insidious poison, and the true magnitude of its past, present, and future harm are yet to be known."