Engine oils are lubricants specifically designed for use in internal combustion engines. They reduce friction between moving parts, helping to prevent wear and tear. Engine oils also help to cool the engine, clean contaminants, and protect against corrosion. They come in various grades and formulations, including synthetic and conventional oils, to meet different engine requirements. The viscosity of engine oil, which indicates its thickness, is crucial for optimal performance. It is measured using a grading system, such as the SAE (Society of Automotive Engineers) scale. Regularly changing engine oil is essential for maintaining engine health and efficiency, as it ensures that the oil remains effective in protecting the engine components.