Use of a lubricant composition to reduce knock in a vehicle engine, said lubricant composition comprising: - at least one base oil, - at least one compound of formula: in which: • R1 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR7 group, an -NR8R9 group; • R2 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR10 group, an -NR11 R12 group; • R3 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR13 group, an -NR14R15 group; • R4 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR16 group, an -NR17R18 group; • R5 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR19 group, an -NR20R21 group; • R6 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR22 group, an -NR23R24 group; • R7, R10, R13, R16, R19 and R22, identical or different, represent independently a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms; • R8, R9, R11, R12, R14, R15, R17, R18, R20, R21, R23 and R24, identical or different, represent independently a hydrogen atom or a saturated or unsaturated, substituted or unsubstituted alkyl group, comprising from 1 to 3 carbon atoms; • at least one of the R1, R2, R3, R4, R5 and R6 groups is different from a hydrogen atom. - at least one base oil, - at least one compound of formula: in which: • R1 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR7 group, an -NR8R9 group; • R2 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR10 group, an -NR11 R12 group; • R3 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR13 group, an -NR14R15 group; • R4 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR16 group, an -NR17R18 group; • R5 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR19 group, an -NR20R21 group; • R6 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR22 group, an -NR23R24 group; • R7, R10, R13, R16, R19 and R22, identical or different, represent independently a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms; • R8, R9, R11, R12, R14, R15, R17, R18, R20, R21, R23 and R24, identical or different, represent independently a hydrogen atom or a saturated or unsaturated, substituted or unsubstituted alkyl group, comprising from 1 to 3 carbon atoms; • at least one of the R1, R2, R3, R4, R5 and R6 groups is different from a hydrogen atom. • R1 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR7 group, an -NR8R9 group; • R2 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR10 group, an -NR11 R12 group; • R3 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR13 group, an -NR14R15 group; • R4 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR16 group, an -NR17R18 group; • R5 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR19 group, an -NR20R21 group; • R6 represents a hydrogen atom, a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms, an -OR22 group, an -NR23R24 group; • R7, R10, R13, R16, R19 and R22, identical or different, represent independently a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group, comprising from 1 to 10 carbon atoms; • R8, R9, R11, R12, R14, R15, R17, R18, R20, R21, R23 and R24, identical or different, represent independently a hydrogen atom or a saturated or unsaturated, substituted or unsubstituted alkyl group, comprising from 1 to 3 carbon atoms; • at least one of the R1, R2, R3, R4, R5 and R6 groups is different from a hydrogen atom.