Combustion analyses of various engines (viz., compression ignition engines, spark-ignition engines, and reaction engines) are vital for improving engine geometry through modifications in the existing engine to facilitate the optimum burning of blended fuels. Various kinds of binary and ternary fuel blends are precursors to electric and hydrogen fuel cell vehicles. Optimizing such fuel blend proportions for reducing emissions requires a fast and effective technique that can be used as a handy tool in automobile industries. Single-zone combustion modeling using modified Wiebe function is an effective and fast technique for analyzing stage-wise combustion in internal combustion engines. In the present study, an improved technique for the estimation of Wiebe function parameters is developed that avoids assuming the value of efficiency parameter ‘a’ or form factor ‘m’ of modified Wiebe functions. The transition points divides the combustion stages accurately. Burn fraction evolution and apparent heat release rate as a function of the crank angle duration are predicted using estimated multiple Wiebe function parameters. The values of root mean square error (< 1 J/°CA for predicted apparent heat release rate) and coefficient of determination (> 0.99) indicate higher predictability of the present model compared to previously reported models in the literature.