How often should a sedan change its engine oil?

[SanCody]

For sedans, mineral oil should be changed within 5,000 kilometers; semi-synthetic oil within 7,500 kilometers; and full-synthetic oil within 10,000 kilometers. More information about engine oil is as follows: 1. Introduction: Engine oil, motor oil, or engine lubricant is a substance enhanced with additives in base oil, primarily containing anti-wear additives, detergents, dispersants, and multi-grade oil viscosity index improvers. 2. Function: The main functions of engine oil are to reduce friction and wear on moving parts, and to remove sludge (one of the functions of dispersants) and varnish (detergents) from the engine. Engine oil also neutralizes acids produced from fuel and lubricant oxidation (detergents), improves the sealing of piston rings, and cools the engine by carrying away heat from moving parts.