Abstract: Use of an unleaded gasoline fuel composition for reducing the occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition internal combustion engine, wherein the unleaded gasoline fuel composition comprises a gasoline base fuel and detergent additive package, wherein the detergent additive package comprises a Mannich base detergent mixture, wherein the mixture comprises a first Mannich base detergent component derived from a di- or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the spark-ignition internal combustion engine is lubricated with a lubricant composition comprising from 1200 ppmw to 3000 ppmw of calcium, based on the total lubricant composition.

Abstract: A fuel composition having an enhanced thermal stability in a diesel fuel application is provided comprising a base fuel containing: (a) 90 to 50% by volume based on the base fuel, of a petroleum refined diesel fuel having sulfur level of less than 500 ppm, and boiling point within the range of about 150 to about 400° C.; (b) 5 to 25% by volume based on the base fuel, a Fischer-Tropsch derived gas oil; and (c) 5 to 25% by volume based on the base fuel, a fatty acid alkyl ester having C18:2 to C18:1 ratio of 1.5 to 2.8 wherein the alkyl group has a carbon number from 1 to 4.

Abstract: A fuel composition having an enhanced thermal stability in a diesel fuel application is provided comprising a base fuel containing: (a) 90 to 50% by volume based on the base fuel, of a petroleum refined diesel fuel having sulfur level of less than 500 ppm, and boiling point within the range of about 150 to about 400° C.; (b) 5 to 25% by volume based on the base fuel, a Fischer-Tropsch derived gas oil; and (c) 5 to 25% by volume based on the base fuel, a fatty acid alkyl ester having C18:2 to C18:1 ratio of 1.5 to 2.8 wherein the alkyl group has a carbon number from 1 to 4.