A Mannich post-treated neutral or overbased calcium salt of a sulfurized alkyl-substituted phenol composition which is a reaction product of: (a) a neutral or overbased calcium salt of a sulfurized alkyl-substituted phenol compound, wherein the alkyl-substituted phenol compound is derived from alkylation of a phenol compound with one or more olefins comprising C 9 to C 18 oligomers of monomers selected from propylene, butylene or mixtures thereof, and wherein the calcium salt of a sulfurized alkyl-substituted phenol compound comprises from 2 to 10 wt. %, by combined mass, of an unsulfurized alkyl-substituted phenol compound and its unsulfurized calcium salt, (b) a source of an aldehyde, wherein the aldehyde is (i) an aliphatic aldehyde selected from formaldehyde, acetaldehyde, propionaldehyde, butraldehyde, valeraldehyde, caproaldehyde and heptaldehyde, or (ii) a formaldehyde producing reagent selected from formalin, formaldehyde oligomers, and polymers of formaldehyde and (c) a primary or secondary monoamine compound having at least one active hydrogen; wherein said Mannich post-treated neutral or overbased calcium salt of a sulfurized alkyl-substituted phenol composition has at least 70% reduced content, by combined mass, of the unsulfurized alkyl-substituted phenol compound and its unsulfurized calcium salt, compared to the content, by combined mass, of the unsulfurized alkyl-substituted phenol compound and its unsulfurized calcium salt present in the non-post-treated neutral or overbased calcium salt of a sulfurized alkyl-substituted phenol composition; and wherein the primary monoamine compound having at least one active hydrogen is represented by the formula HNRR 1, wherein one of the radicals R or R 1 is hydrogen and the other radical is a C 1 -C 6 straight or branched alkyl chain radical; the secondary monoamine compound having at least one active hydrogen is represented by the formula HNRR 1, wherein R or R 1 are the same or different and are C 1 -C 30 hydrocarbyl radicals; wherein the reaction is carried out employing a molar ratio of the salt of the sulfurized alkylhydroxyaromatic composition to aldehyde to monoamine compound ranging from 1:1:1 to 1:10:10; and the reaction conditions in step (b) include a temperature ranging from 70 °C to 180 °C and a time period for the reaction ranging from 30 minutes to 14 hours; and wherein the reaction is carried out in the presence of a solvent, wherein the solvent is an aromatic hydrocarbon solvent, an alcohol solvent or a mineral lubricating oil. (a) a neutral or overbased calcium salt of a sulfurized alkyl-substituted phenol compound, wherein the alkyl-substituted phenol compound is derived from alkylation of a phenol compound with one or more olefins comprising C 9 to C 18 oligomers of monomers selected from propylene, butylene or mixtures thereof, and wherein the calcium salt of a sulfurized alkyl-substituted phenol compound comprises from 2 to 10 wt. %, by combined mass, of an unsulfurized alkyl-substituted phenol compound and its unsulfurized calcium salt, (b) a source of an aldehyde, wherein the aldehyde is (i) an aliphatic aldehyde selected from formaldehyde, acetaldehyde, propionaldehyde, butraldehyde, valeraldehyde, caproaldehyde and heptaldehyde, or (ii) a formaldehyde producing reagent selected from formalin, formaldehyde oligomers, and polymers of formaldehyde and (c) a primary or secondary monoamine compound having at least one active hydrogen; wherein said Mannich post-treated neutral or overbased calcium salt of a sulfurized alkyl-substituted phenol composition has at least 70% reduced content, by combined mass, of the unsulfurized alkyl-substituted phenol compound and its unsulfurized calcium salt, compared to the content, by combined mass, of the unsulfurized alkyl-substituted phenol compound and its unsulfurized calcium salt present in the non-post-treated neutral or overbased calcium salt of a sulfurized alkyl-substituted phenol composition; and wherein the primary monoamine compound having at least one active hydrogen is represented by the formula HNRR 1, wherein one of the radicals R or R 1 is hydrogen and the other radical is a C 1 -C 6 straight or branched alkyl chain radical; the secondary monoamine compound having at least one active hydrogen is represented by the formula HNRR 1, wherein R or R 1 are the same or different and are C 1 -C 30 hydrocarbyl radicals; wherein the reaction is carried out employing a molar ratio of the salt of the sulfurized alkylhydroxyaromatic composition to aldehyde to monoamine compound ranging from 1:1:1 to 1:10:10; and the reaction conditions in step (b) include a temperature ranging from 70 °C to 180 °C and a time period for the reaction ranging from 30 minutes to 14 hours; and wherein the reaction is carried out in the presence of a solvent, wherein the solvent is an aromatic hydrocarbon solvent, an alcohol solvent or a mineral lubricating oil.