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Lubrication of advanced high temperature engines has been one of the greatest obstacles in the development of the Adiabatic engine. Liquid lubricants which gave lubricating properties as well as heat removal function can no longer carry out this duty when piston ring top ring reversal temperatures approach 540°C. Solid lubricants offer some hope. Since solid lubricants cannot perform the heat removal function, its coefficient of friction must be very low, at least <0.10, in order to prevent heat build up and subsequent destruction to the piston rings and cylinder liners. The Hybrid Piston concept developed in the U.S. Army Advanced Tribology program offers some hope, since the top solid lubricant ring slides over the bottom hydrodynamic lubricant film section during each stroke. This paper presents the progress made with the solid lubricant top ring in the Hybrid Piston. Four materials have shown promise in the laboratory to fullfil its mission.