This paper presents a comprehensive review of the technical feasibility of biomass-derived combustible gaseous fuels and low-calorific-value biomass as a feedstock for combustion engines. The mixture of combustible gases (producer gas) can be generated from biomass and successively used for power generation from combustion engines. The producer gas can be used in dual fuel mode in compression-ignition engines. The present review covers the modifications suggested for the feasibility of producer gas as a feedstock in diesel engines. The effects of modification in diesel engine parameters, namely compression ratio, injection timing, and injection pressure, are extensively reviewed. This paper assesses the impact of these engine parameters on fundamental combustion processes with producer gas. There is a broad impression in the literature that the operation and performance of combustion engines are significantly impacted by using producer gas as a fuel. The impact of this feedstock on engine performance and tailpipe emissions is also covered. The effect of versatile management of pilot fuel, combustion chamber geometries, type of carburetors, and producer gas quantity on the engine characteristics are discussed.