This paper presents a comprehensive study on using MO (mahua oil) as fuel effectively in a diesel engine by adopting emulsification and TBC (low heat rejection) techniques. A mono cylinder diesel engine was used for the study. Initially trials were made on the engine using neat diesel (ND), neat mahua oil (NMO) as fuels. In the second phase, NMO was converted into its stable emulsion (called as MOE) and tested in the engine. Finally thermal barrier coating of 0.2 mm was made on the piston, valves and cylinder head of the engine using the ceramic power of Al2O3 and the engine was tested using NMO and MOE as fuels in the TBC engine to improve the part load performance of the engine with MOE as fuel. Results indicated improvement in BTE (brake thermal efficiency) with MOE as compared to NMO mainly at high power outputs in the unmodified engine. The maximum BTE was found as 31.5% with ND, 27.2% with NMO and 30.4% with MOE at the peak power output. Reduced smoke, HC (hydrocarbon), CO (carbon monoxide) and NOx (oxides of nitrogen) emissions were found with MOE mainly at high power outputs. Engine with TBC mode significantly increased the performance and reduced all the emissions (except NOx) at all power outputs with both NMO and MOE. Cylinder peak pressure and maximum rate of pressure rise were improved sufficiently with MOE as compared to NMO mainly at high power outputs in the unmodified engine. The peak cycle temperature was noted to be lower with MOE as compared to NMO. It rose in TBC mode with MO and MOE as fuels. Heat release rate showed enhanced combustion rate at the initial stage with MOE as fuel. TBC mode significantly improved the combustion at all power outputs with both NMO and MOE. Shorter ignition delay and combustion duration were noted with both MO-TBC and MOE-TBC at all power outputs. It was concluded that combining emulsification and TBC techniques could improve the performance and combustion of a diesel engine significantly with considerable reduction in all emissions using MO as fuel.