Combustion reaction in the internal combustion engine depends on many different variables, one of the most important factors in an efficient combustion reaction is the ability of the reactants, the fuel molecules and the oxidant molecules, to interact with each other, Most fuels used in internal combustion engines are in liquid state, like gasoline, diesel, biofuels, and since combustion occurs in the gas phase, achieving a substantially even dispersion of fuel molecules among oxidant molecules can prove difficult due to the vapor pressure of the liquid, Therefore, an efficient combustion reaction would involve providing for the fuel molecules to be substantially and evenly dispersed throughout the oxidant molecules, thereby allowing sufficient interactions between the reactants and promoting the combustion reaction. Conventional systems and methods attempt to remedy this problem by increasing the quantity of gas phase fuel molecules by increasing the temperature of the liquid fuel to increase the vapor pressure. The present invention has been developed in response to the present state and in particular, in response to the problems and needs that have not yet been fully solved by currently available conventional system. Hence we have designed a new fuel supply system where the petrol/biodiesels (having low viscosity) is atomized using the ultrasonic sounds and allowing it to pass through the convective pre-heater where the atomized fuel is converted in to the vapor form (gaseous form) using the exhaust gases from the outlet valve of the engine ,which are at the sufficient temperatures to vaporize the bio-diesels and study of these system behavior by using bio-diesel as alternative fuel in the vapor form in the present petrol engine and to check the emission like CO, HC from the exhaust gasses of petrol engine with a 4-s petrol engine. The project’s goal is to develop specific knowledge as to whether these methods will increase the efficiency and oil is an acceptable supplemental fuel.