They usually come in green bottles (STP, Lucas), I thought ethanol was considered clean burning, the STP bottle says it's for E10, E15 and E85."fight fuel economy loss due to ethanol fuel deposits, prevent rust and corrosion, save gas and lower emissions by removing fuel system deposits " treats up to 21 gallons, "for ethanol fuels". Has anybody used this type of FS cleaner in a regular IC engine and what do you think it mainly is, a lubricant like marvel mystery oil?