Abstract
Currently, downsizing concept in combination with turbo-GDI engines is used to reduce CO2 and improve fuel efficiency. They have made significant contribution in maximizing the potential of gasoline engine. However, there is still limitation of engine efficiency when operating in the full-load range due to component protection and knock. In this study, water injection system is proposed to improve fuel efficiency. Water injection is already a well-known technology that has been used in motor sports and aviation industry. Water is more effective compared to gasoline when it comes to absorbing heat energy with a latent heat of vaporization. By absorbing more heat energy, the in-cylinder temperature is reduced and ignition timing can be advanced to get increased power. This study experimentally investigated how a water injection system can be a solution to reduce fuel consumption and CO2 emission.