In-Cylinder Fuel and Lubricant Effects on Gasoline Engine Friction

Reducing engine friction remains an important goal of the automotive industry. Reduced engine friction has been partly achieved by using low viscosity, friction modified lubricants, reducing the energy required to shear the fluid in the hydrodynamic lubrication regime (which is the primary lubrication mode in the piston assembly). It has long been understood that the piston ring / cylinder liner interface is responsible for a significant proportion of engine friction and can significantly influence the fuel consumption of an engine. This paper describes research conducted to develop understanding of both the interfacial relationship of the compression ring and cylinder liner and the synergistic relationship of fuel and lubricant at the top ring zone of a single cylinder gasoline engine. A portfolio of engine testing, laboratory work and computer simulation has been conducted.