What chemicals are used as additives in gasoline?
MTBE (methyl- tert- butyl ether) - toxic and penetrates ground water ethanol methanol isopropanol and a couple more ols and a lot more!
oxygenators (chemicals that supply oxygen atoms); currently ethanol is used. Methyl t-butyl ether was previously used but is banned because it ends up in the ground water (from underground leaking fuel tanks). Other addition like TCP (tri-cresyl phosphate; tolyl phosphate) from Shell are added as proprietary additives that are said to help the engine stay clean, etc.