A lubricant additive, method for reducing a boundary friction coefficient of a lubricant composition, and method for improving fuel economy. The additive includes a synergistic mixture of a) a metal-containing phosphorus antiwear compound derived from at least one secondary alcohol in an amount sufficient to provide the lubricant composition with from about 200 to about 1000 ppm by weight phosphorus, and b) a polyol derived from a diol and a mono-ol having a diol to mono-ol molar ratio ranging from about 0.3:1 to about 2.0:1, wherein the diol contains from 6 to 36 carbon atoms and the mono-ol contains from 12 to 16 carbon atoms. The polyol is present in the lubricant additive in an amount sufficient to provide a synergistic reduction in the boundary friction coefficient of the lubricant composition in combination with component (a).