A complex alcohol ester which comprises the reaction product of an add mixture of the following: a polyhydroxyl compound represented by the general formula: R(OH)n wherein R is any aliphatic or cyclo-aliphatic hydrocarbyl group and n is at least 2, provided that the hydrocarbyl group contains from about 2 to 20 carbon atoms; a polybasic acid or an anhydride of a polybasic acid, provided that the ratio of equivalents of the polybasic acid to equivalents of alcohol from the polyhydroxyl compound is in the range between about 1.6:1 to 2:1; and a monohydric alcohol, provided that the ratio of equivalents of the monohydric alcohol to equivalents of the polybasic acid is in the range between about 0.84:1 to 1.2:1; wherein the complex alcohol ester exhibits a pour point of less than or equal to -20 DEG C, a viscosity in the range between about 100-700cST at 40 DEG C and having a polybasic acid ester concentration of less than or equal to 70 wt.%, based on the complex alcohol ester.