A Lubricated System Comprising a DLC Surface

The present invention relates to a lubricated system comprising: a) a component comprising a first surface which is a diamond-like carbon (DLC) surface; b) a component comprising a second surface; and c) a lubricant formulation interposed between the first surface and second surface. The lubricant formulation comprises: i) a base stock; ii) a molybdenum compound; iii) an organic polymer comprising a hydrophobic polymeric sub unit selected from polyesters and functionalised polyolefins and a hydrophilic polymeric sub unit selected from polyethers; and iv) optionally, other additives. The combination of the molybdenum compound and the organic polymer in the lubricant formulation reduces the wear on one or more of the surfaces in the lubricated system when compared with using the molybdenum containing friction modifier alone.