Gasoline compositions

1. A gasoline composition comprising

(i) a base gasoline having an E70 base value and an E100 base value; and

(ii) an oxygenate composition comprising

component A and at least one component selected from components B, C, D and E, wherein:

component A is an alkyl alkenoate compound, or a mixture of alkyl alkenoate compounds, selected from compounds of formula I:

wherein R 1 is a linear alkenyl group containing 3 to 5 carbon atoms, optionally substituted by a methyl group, and R 2 is a linear or branched alkyl group containing 1 to 6 carbon atoms, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.;

component B is ethanol;

component C is a compound of formula II or formula III:

wherein the R 3 , R 4 , R 5 and R 6 groups are independently selected from hydrogen and C 1-6 hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.;

component D is butanol; and

component E is an ether of the general formula IV:

R 7 —O—C(Me) 3   (IV)

wherein R 7 is selected from methyl, ethyl or mixtures thereof;

wherein the gasoline composition has an E70 value and an E100 value;

wherein the oxygenate composition maintains the E70 value and E100 value of the gasoline composition within 25% of the E70 base value and the E100 base value, respectively.

2. The gasoline composition of claim 1 wherein in component A, the R 1 group is a linear or branched alkenyl group containing 3 or 4 carbon atoms, and the R 2 group is a linear or branched alkyl group containing 2 to 4 carbon atoms.

3. The gasoline composition of claim 1 wherein component A is ethyl pentenoate.

4. The gasoline composition of claim 3 wherein component A is a mixture of isomers of ethyl pentenoate.

5. The gasoline composition of claim 1 wherein at least component C is selected and in component C, the R 4 and R 5 groups are hydrogen, the R 3 and R 6 groups are independently selected from hydrogen and C 1-6 hydrocarbyl groups, with at least one of the R 3 and R 6 groups being a C 1-6 hydrocarbyl group, and with the proviso that component C has a boiling point or boiling point range of at most 100° C.

6. The gasoline composition of claim 5 wherein component C is selected from 2-methyl furan, 2,5-dimethyl furan and mixtures thereof.

7. The gasoline composition of claim 1 wherein said oxygenate composition comprises

component A and at least one component selected from each categories (a) and (b) below:

(a) component B, and

(b) one component selected from components C, D and E.

8. The gasoline composition of claim 1 wherein the base gasoline is unleaded.

9. The gasoline composition of claim 8 , wherein the concentration of the oxygenate composition is in the range of from 0.5 to 40% vol., based on the gasoline composition.

10. The gasoline composition of claim 1 , wherein the oxygenate composition maintains the E70 value and E100 value of the gasoline composition within 20% of the E70 base value and the E100 base value, respectively.

11. The gasoline composition of claim 10 , wherein the oxygenate composition maintains the E70 value and E100 value of the gasoline composition within 15% of the E70 base value and the E100 base value, respectively.

12. The gasoline composition of claim 1 wherein the oxygenate composition maintains the sum of E70 and E100 values within 15% of the sum of E70 base and E100 base values.

13. The gasoline composition of claim 12 wherein the oxygenate composition maintains the sum of E70 and E100 values within 10% of the sum of E70 base and E100 base values.

14. The gasoline composition of claim 13 wherein the oxygenate composition maintains the sum of E70 and E100 values within 5% of the sum of E70 base and E100 base values.

15. The gasoline composition of claim 1 wherein at least component B is selected, and the concentration of component A is at least 50% vol. and the concentration of component B is at most 50% vol., based on the oxygenate composition.

16. The gasoline composition of claim 1 wherein at least component C is selected, and the concentration of component A is at most 70% vol. and the concentration of component C is at least 30% vol., based on the oxygenate composition.

17. The gasoline composition of claim 1 wherein at least component D is selected, and the concentration of component A is at most 50% vol. and the concentration of component D is at least 50% vol., based on the oxygenate composition.

18. The gasoline composition of claim 1 wherein at least component E is selected, and the concentration of component A is at most 50% vol. and the concentration of component E is at least 50% vol., based on the oxygenate composition.

19. The gasoline composition of claim 1 wherein at least components B and C are selected, and the concentration of component A is at least 23% vol., the concentration of component B is at least 0.1% vol., and the concentration of component C is at least 0.1% vol., based on the oxygenate composition.

20. The gasoline composition of claim 1 wherein at least components B and D are selected, and the concentration of component A is at least 0.1% vol., the concentration of component B is at least 0.1% vol., and the concentration of component D is at least 0.1% vol., based on the oxygenate composition.

21. The gasoline composition of claim 1 wherein at least components B and E are selected, and the concentration of component A is at least 10% vol., the concentration of component B is at least 0.1% vol., and the concentration of component C is at least 0.1% vol., based on the oxygenate composition.

22. The gasoline composition of claim 1 wherein the oxygenate composition comprises component A and at least two components selected from components B, C, D, and E.