An oil additive is a chemical compound that improves the lubricant performance on the engine oil. Oil additives are also used to slow down oxidation, prevent deposits and foam formation. Some of the most common oil additives include: · Antioxidants · Anti-wear agents · Detergents · Dispersants · Foam inhibitors · Friction modifiers · Viscosity-index improvers · Pour-point depressants · Rust and corrosion inhibitors