This paper presents experimental study on the impact of using fuels with different physical and chemical properties in a diesel engine. Research is driven towards finding an alternative or extender to the conventional diesel fuel for compression ignition engines. Such alternative fuels have wide ranges of physical and chemical properties which are not suitable for CI engines. Advanced injection systems and control strategies in modern diesel engines permit operation to be extended to a wider range of fuels. Therefore, experimental investigation to understand the effects of different fuels on engine performance, combustion, and emissions are necessary.The study covers the effect of using different fuels such as JP-8 and Sasol-IPK on a modern automotive diesel engine. The engine used in this study is a 2.0L, 4 cylinders, direct injection diesel engine fitted with piezo-driven injectors. Comparative results of three fuels are presented in terms of performance, fuel consumption, auto-ignition and emission considering ULSD as a baseline fuel. This work aims to identify the possibility of using jet fuels in a modern automotive diesel engine without any modifications. In addition, the combustion process was monitored using cylinder pressure transducer and ion current sensor. Ion current signal characteristics during the operation with the three fuels and its correlations with combustion parameters and emissions are presented.