A method for reducing sulfur and lowering viscosity in bunker oil by the steps of passing bunker oil over a core that ionizes the bunker oil with an electrostatic charge. The core consists of a metal bar being made of an alloy comprising, by weight, 40-70% copper, 10-32% nickel, 15-40% zinc, 2-20% tin and 0.05-10% silver. The metal bar of the core comprises a plurality of grooves, which allows the bunker oil to be agitated as it comes in contact with the core, activating an electrostatic charge. The electrostatic charge of the core creates a magnetic catalytic reaction that causes: (1) a molecular separation in molecular chains within the bunker oil thereby lowering the viscosity of the bunker oil and (2) sulfur to merge with metals and create metal sulfides in the bunker oil thereby reducing the sulfur in the bunker oil.