A decrease of oil consumption in the modern truck engine would mean decrease of particulate matter and hydrocarbon emissions. This decrease has a positive impact on the environment. One important source of oil consumption is the piston/piston-ring/liner system. One way of decreasing oil consumption is to optimize the surface topography of the liner. In this study different liner surfaces and different piston rings were investigated. The investigation shows that it is possible to decrease both the oil film thickness and the friction without sacrificing wear properties of the piston-liner system. A new surface parameter for quick wear estimation of this system is presented. Copyright © 2005 by ASME.