The demand for energy is a significant topic in both developing and developed nations. The need for energy is growing rapidly every day. Biodiesel is a viable alternative answer to this issue, hence it is vital to discover an environmentally friendly alternative solution. To compare the emissions and combustion behaviors while diesel engines employing with Pithecellobium dulce seed oil. As a catalyst, seed oil biodiesel that has been blended separately and mixed with nanoparticles of titanium oxide and aluminum oxide is employed. Transesterification was used to esterify Pithecellobium dulce Seed Oil. Then, for each nano substance, samples S1, S2, and S3 were generated using a sonication technique. The project's focus is on creating a substitute fuel for everyday use. Hydrocarbon‐based gasoline is currently a dependable fuel. Alternatives that are environmentally friendly, like biodiesel, should be taken into account. The main objective of this experiment is to determine the engine performance and emission parameters of diesel engines using mixes of diesel and biodiesel with nano additives. The experiment's fuel is diesel, and an equal volume of biodiesel is mixed with different‐sized nano additives.