The Response Surface Methodology (RSM) optimization technique was used to examine the effect of load, Tomato Methyl Ester (TOME), and Ethanol injection enhanced diesel on engine performance and exhaust gas emissions with a normal piston and an Al2O3 coated piston. TOME biodiesel (10, 20, and 30%) and ethanol (10, 20, and 30%) were chosen to increase BTE while minimizing BSFC, NOx, CO, smoke, and HC. The RSM technique was used to operate the engine by load (0–100%). The results revealed that engine load, TOME, and ethanol concentration all exhibited a considerable effect on the response variables. The ANOVA results for the established quadratic models specified that for each model, an ideal was discovered by optimizing an experiment's user-defined historical design. The present research efforts to improve the performance of a diesel engine by using a thermal barrier-coated piston that runs on biodiesel blends. Al2O3 is the chosen material for TBC due to its excellent thermal insulation properties. B20E30 has a 4% higher brake thermal efficiency than diesel, but B10E20 and B30E20 mixes have a 3.6% and 12% reduction in BSFC. The B20 blends lowered CO and HC emissions by 6% and 8% respectively. In terms of performance and emissions, biodiesel blends performed similarly to pure diesel, and the combination was optimized through the design of an experiment tool. © 2024 Elsevier B.V., All rights reserved.