It is essential to maintain the environment by preserving the ecological balance of the area and keeping an eye on emission regulations. It's common knowledge that fossil fuels are the backbone of the transportation industry. Over time, the atmospheric concentrations of carbon
and nitrogen oxides have risen dramatically due to human activities, particularly the burning of fossil fuels at excessive rates. Long-term sustainability may be attainable with the implementation of a bio-based, circular economy. Fears of a future fuel shortage and the negative effects on the environment spurred researchers to search for more sustainable energy sources. Renewability, reduced emissions, biodegradability, and better lubricating characteristics are just some of the reasons why biodiesel is becoming increasingly popular as a viable alternative to petroleum diesel. In this research paper, biodiesel extracted from cerbera odollam seeds was tested for its performance and emission characteristics on a low-heat rejection diesel engine
with its piston coated with nano coating. The results were compared with those of a standard diesel engine, BCO25 at coated piston engine enhances break thermal efficiency by over 5.5%, consumes less fuel by 6.4%, reduces CO by 5.9%–10.7%, and reduces UBHC by 4% to 8.5%.