Friction Reduction in Power Cylinder Systems for Downsize Gasoline Engines with Modern Surface Technologies of Aluminum Crankcases

Downsized gasoline engines for passenger cars requiring low CO₂ emissions trend to lightweight designs using AlSi material for crankcases. For ultra-low vehicle fuel consumption a low friction and lightweight power cylinder system (PCS) has been developed containing a new lightweight piston design and current cylinder surface technologies such as structured honed AlSi or iron spray coating (PTWA) as well as related piston ring surface technologies such as DLC and PVD coatings. Component and system analysis for optimizing the design, materials used and design features are reviewed, along with PCS functionality, NVH and friction testing results. The breakdown to component friction reduction is summarized using synergies from friction simulation and engine friction measurement.