The current experimental study aims to investigate the effect of magnetic field on internal combustion engines. The study concentrates on engine performance by examining fuel consumption and exhaust emissions. The magnetic field was applied to the fuel supply line of a typical SI engine using unleaded gasoline fuel. Moreover, the magnetic field was generated by electromagnets with a twelve-volts car battery while varying the strength and configuration of the magnetic field. The experiments were conducted at a variety of engine operating conditions by using an engine dynamometer setup. The exhaust gas emissions of CO, NOx, and HC were measured by using an online gas analyzer. The magnetic effect on SFC reduction was only consistently significant at the lowest load of 20 Nm and both speed extremes of 1000 and 3000 rpm using one magnet. The effect on CO was the most significant reduction of all other emissions at most engine’s loads and speeds, especially at lowest speed of 1000 rpm using five magnets. The effect on NOx was the most consistent reduction of all others with the most effect using the ‘Spiral’ configuration at lowest speed of 1000 rpm.