Cylinder Bore Finishes and Their Effect on Oil Consumption

New emission requirements (PZEV and ULEV) have sparked interest in further improvement in engine oil consumption. This paper reviews measurement equipment and parameters currently used to describe bore finish, as well as recent research on bore finish effects on oil consumption. Typical bore finishes in use are benchmarked for a number of engines, and recommendations are presented for future finishes. The paper closes with some case histories illustrating bore finish effects on oil consumption and current problems in this area.