> The chemical makeup of it? The government banned tetra ethyl lead in it, and mandated some ethanol in it, but the rest is various mixes made by the gas compan

> The chemical makeup of it? The government banned tetra ethyl lead in it, and mandated some ethanol in it, but the rest is various mixes made by the gas companies. There's a mil-spec gasoline that has to contain exact proportions of specific alkanes and ethanol to very tight tolerances, that could be taken as the golden standard gasoline.