New tribo-systems composed of green chemicals have been investigated. Compatibility of friction modifiers with DLC was evaluated by using SRV test machine. A Zn-free lubricant formulation showed a steady-state friction coefficient of 0.15 for steel/steel contact. Hydrogenated DLC coating showed similar tribological properties when slid against steel. Interestingly, this lubricant showed low friction coefficient of 0.02 for hydrogen-free amorphous DLC when slid against steel. A model friction modifier improved the running-in performance and reduced wear for hydrogen-free DLC, while it marginally increased steady-state friction coefficient up to 0.04. The importance of material–lubricant combination and lubrication model has been highlighted