Abstract
KEYWORDS – Performance, CO2, Efficiency, Variable Compression Ratio, VCR
ABSTRACT
Downsizing represents the main technology trend for meeting climate relevant CO2 emission standards in gasoline engine applications. Turbocharging is required to maintain or even increase the power of smaller engines, however generally leads to a reduced compression ratio in order to avoid knock at high engine loads. During part load operation, engine thermal efficiency suffers under reduced compression ratio. The application of a variable compression ratio (VCR) system can solve this general conflict between maximum power and engine efficiency and can enable high performance and high efficiency powertrains. This paper derives the potential of VCR in automotive engines and highlights synergies available in applications with variable compression ratio.