Abstract: Syngas is considered to be a viable alternative fuel to fossil derived fuels in both gas turbines and reciprocating gas engines. Detail studies of syngas as a dual fuel in compression ignited engine, diesel as a pilot fuel and as a single fuel in a naturally aspirated spark ignited engines are found in the literature. Even though the prospect of fuelling naturally aspirated spark ignition engine with syngas is very promising and even cost competitive with that of natural gas, it is associated with power de-rating that is mainly provoked by the decrease in volumetric efficiency. With the advancement in gasification technology and stern regulation with both fossil derived fuels and solid bio-energies, detail investigation of syngas’s combustion parameters and their effect in an internal combustion engine is very important. This study presents the combustion features like calorific value, laminar flame velocity and flammability limits of syngas in detail and their effects on the combustion in an internal combustion engine, spark ignition engine in particular. The study shows that understanding of the combustion characteristics of syngas is very important to investigate the effect of diluting inert gases on the overall performance and emission. The fact that the proportion of the constituent gases of syngas produced from gasification varied with variation of input parameters, there is limitation in the characterization of both laminar flame speed and flammability limit.