The Effect of Gasoline-Bioethanol Blends to The Value of Fuel’s Octane Number Cahyo Setyo Wibowo, Bambang Sugiarto, Ardi Zikra, Alva Budi, Try Mulya and Maymuchar E3S Web Conf., 67 (2018) 02033 Published online: 26 November 2018 DOI: 10.1051/e3sconf/20186702033