disclosed is a lubricant composition for use in association with a device involving metal - to - metal contact of moving parts , the composition comprising a base stock comprising at least one low viscosity poly - alpha - olefin ; a viscosity improver comprising at least one high viscosity poly - alpha - olefin ; and a performance additive comprising at least one compound effective to improve at least one property of the lubricant and / or the performance of the equipment in which the lubricant is to be used .