A Study of Compressed Natural Gas Fuelling in a Downsized and Boosted, Multi-Cylinder, Direct Injection Spark-Ignition Engine

Abstract

Improvement in the fuel economy of the internal combustion engine is imperative given the demand of increasingly strict fleet average carbon dioxide (CO2) emissions limit. Compressed natural gas (CNG) has emerged as a promising automotive fuel to meet this demand due to its favorable fuel properties. However, today's CNG fuelled engines with port fuel injection technology have inferior peak performance compared to gasoline direct injection (GDI) engines, primarily due to lower volumetric efficiency. CNG direct injection technology has the potential to overcome these limitations. Therefore, this study investigates the performance of a 4-cylinder, downsized and boosted, spark-ignited producti..