Abstract: A gasoline additive and method for making such additive wherein bituminous coal is successively immersed into a mixture of (1) mineral spirits and carbide, (2) a ketone and carbide, and (3) benzene and carbide, for a period of from about 10 to 30 hours in each mixture. The mixtures are then combined and to 100 parts by volume thereof are added, by volume, 60 parts methyl isobutyl ketone, 300 parts orthodichlorbenzene, 370 parts mineral spirits and 75 parts tri-o-cresyl phosphate. When this final mixture is added to gasoline in an amount of about one ounce per ten gallons of gasoline, automotive vehicles - operating on such gasoline have their mileage per gallon of gasoline improved up to about thirty to forty percent and more.