The cause of smoke is incomplete combustion which may be due to incorrect air-fuel ratio or may be due to improper
mixing of fuel with air. As shown in Fig. 8, significant difference is observed between smoke density of various fuels at no
load and full load, but the change was very insignificant at low load of the engine. In dual fuel mode of operation, the smoke
density is observed to be higher than that of the DF for all combination of PG. In diesel operation, the smoke density
attained a maximum value of 25% where as it is found to be 32% in dual fuel mode for D+PG8 at full load.