This research aimed to explore the experimental analysis of biodiesel production from the peels of Citrus limetta and Citrus limon. Thermogravimetric analysis and attenuated total reflection spectroscopy were carried out to evaluate the thermal behaviour and chemical composition of the materials, which revealed that the feedstocks were suitable for biodiesel production. The trans-esterification process was responsible for the preparation of various blends, which were assayed for the performance and emission characteristics of the engine. The performance and emission characteristics of a single-cylinder engine fuelled with diesel and its blends with biodiesel were tested in terms of brake thermal efficiency, specific fuel consumption, and CO, HC, NO, and smoke emissions. Based on the obtained results, it is evident that pure diesel fuel had the highest brake thermal efficiency. Moreover, blends with a high fraction of biodiesel had relatively similar performance and emission characteristics. Overall, blends with high proportions of biodiesel generally produced slightly greater amounts of carbon monoxide, hydrocarbons, nitrogen oxides, and smoke than diesel fuel. However, the values of the abovementioned variables were relatively small, indicating similar environmental impacts for the tested compositions of the blend.