“…Investigation of n-butanol usage as the engine fuel has been conducted for some researchers. In diesel engines, especially, the research groups, represented by Yao et al [10,11], Liu et al [12,13], Rakopoulos et al [14,15], and the author [16,17] have investigated the characteristics of n-butanol blended with diesel combusted in diesel engines. On conventional port fuel injection (PFI) spark ignition (SI) engines, on the other hand, the majority of studies on n-butanol have been performed either as pure fuel or blend fuel due to its high octane number.…”