Numerous factors continuously drive the need to increase the efficiency of internal combustion engine (ICE) used in a variety of applications; such as on-road transportation vehicles, stationary power, marine and off-road vehicles. ICEs can be fueled by gasoline, diesel, natural gas, and ethanol. One of the key contributions to ICE efficiency is the tribology of the ring and liner interface. Friction must be minimal in the ring and liner system without compromising the reliability (scuffing prevention) and durability (wear prevention) of the system. Several approaches are used to achieve satisfactory performance, including lubricant, materials and surface texture technologies. Effective integration of these technologies is essential to minimize friction, ensure reliability and durability of engines. Testing and evaluation of these technologies in an engine is an expensive proposition. Thus, there is a need for an effective approach to investigate the tribological phenomena and efficiently evaluate the impact of various technologies on friction, wear and scuffing of ring and liner system. This paper present one such approach. In-use engine ring and liner specimen were characterized to determine the salient basic wear and scuffing mechanisms, the nature and characteristic of tribochemical surface films formed from the engine lubricant additives. A combination of several analytical techniques were used. Nano-mechanical properties of the tribochemical surface films were also assessed by nano-indentation technique. The changes in the near-surface region of the liner specimen during wear and scuffing damage were also characterized by cross-sectional metallographic technique. Results of these various analyses from in-use engine component, presented in this paper, should provide the basis for the development of an effective and efficient lab test method to evaluate ICE ring and liner wear and scuffing behavior.