Fuel compositions
A fuel composition comprising a base fuel and at least one viscosity index (VI) improving additive, wherein the viscosity index (VI) improving additive is a functionalized dispersant olefin copolymer. The viscosity index (VI) improving additive provides improved power output and/or acceleration characteristics.
1. A diesel fuel composition comprising a diesel base fuel and at least one viscosity index (VI) improving additive, wherein the viscosity index (VI) improving additive is a functionalized dispersant olefin copolymer produced from reacting an olefin copolymer with a functionalizing component selected from amines, amides, nitrogen-containing heterocyclic compounds or alcohols or produced from grafting an olefin copolymer with a grafting material and then reacting the grafted material with a functionalizing component selected from amines, amides, nitrogen-containing heterocyclic compounds or alcohols, wherein the olefin copolymer is a copolymer of ethylene with a C 3 to C 20 olefin, and wherein the concentration of the viscosity index (VI) improving additive in the fuel composition is from 0.001 to 1% w/w.
2. The fuel composition according to claim 1 wherein the C 3 to C 20 olefin is selected from propylene, butylene, butadiene, isoprene, and mixtures thereof.
3. The fuel composition according to claim 1 wherein the olefin copolymer is a copolymer of ethylene and propylene.
4. The fuel composition according to claim 1 wherein the grafting material is an unsaturated acid.
5. The fuel composition according to claim 1 wherein the grafting material is maleic anhydride.
6. The fuel composition according to claim 1 wherein the functionalizing component is an amine.
7. The fuel composition according to claim 6 wherein the amine is an aromatic amine.
8. The fuel composition according to claim 7 wherein the aromatic amine is N-phenyl-1,4-phenylenediamine.
9. The composition according to claim 1 wherein the concentration of the viscosity index (VI) improving additive in the fuel composition is from 0.001 to 0.5% w/w.
10. A method operating an internal combustion engine, and/or a vehicle which is powered by such an engine, which method involves introducing into a combustion chamber of the engine a fuel composition according to claim 1 .
11. The composition according to claim 9 wherein the concentration of the viscosity index (VI) improving additive in the fuel composition is from 0.025 to 0.25% w/w.
12. A method for improving the power output of an internal combustion engine and/or a vehicle which is powered by such an engine, which method involves introducing into a combustion chamber of the engine a fuel composition according to claim 1 and combusting said fuel composition in said engine.