Abstract
Super lean burn is conceived as a method for improving the thermal efficiency of SI engine. Also, to improve the thermal efficiency, the ignition timing is advanced to advance the combustion phase. However, when the combustion phase is excessively advanced, knocking occurs, which hinders the improvement of thermal efficiency. It is necessary to avoid knocking because the amplitude of the large pressure wave may cause noise and damage to the engine. In this study, SIP surrogate fuels (S5H, S5R) were used to investigate the effect of differences in fuel compositions on knocking characteristics in lean burn SI engine. It was found that toluene suppresses knocking and n-heptane promotes in five fuel components.
