Thanks to the Clean Air Act, the Environmental Protection Agency regulates fuel and fuel additives used in cars (and other engines) because burning gasoline contributes to pollution.
The actual regulation is 40 CFR Part 80 (“Regulation of Fuels and Fuel Additives”): subparts A (general provisions, applying to all 40 CFR Part 890 fuels programs), B (controls and prohibitions), C (oxygenated gasoline), D & E (reformulated gasoline), G (detergent gasoline program), H & O (gasoline sulfur) and J & L (gasoline toxics).
長話短說，所有的汽油都基本一樣
