This study presents ethanol's fabrication by fermenting the golden trumpet flower (Allamanda schottii L) with the yeast strain Saccharomyces cerevisiae. The changes in different parameters during fermentation were studied and optimized while producing the ethanol and the end product was subjected to emission test study by blending petrol and ethanol. The Allamanda floral substrate contains 65% polysaccharides. The strain S. cerevisiae was obtained in the form of baker’s yeast from a domestic shop. For 100 ml of slurry, the highest bioethanol yield recorded was about 18.75 ml via optimization of different culture conditions, including a 1:8 ratio for slurry preparation, maintained under 35 ⁰C, 5.5 pH, 72 h. old inoculum with a quantity of 3.75 g 100 ml−1, fermented for120 h. The highest yield of bioethanol was acquired under the addition of urea. This technique & design is capable of industrial-scale fabrication of bioethanol by using A. schottii floral substrates. This research was conducted to fabricate ethanol by fermentation (A. schottii L) floral substrate with S. cerevisiae. The optimum physiochemical parameters required to obtain the highest yield of bioethanol from A. schottii flower by fermentation was studied. The immobilization strategy with a cheap agricultural substrate and magnetic nanoparticles were also studied. The engine performance and emission studies were done with different blends of petrol and bio-ethanol.