How often should the gear oil in a new car be changed?

[RonanDella]

New car gear oil should be changed every 60,000 kilometers to effectively improve the efficiency of transmitting engine power through the gears. When changing the oil, viscosity selection is a fundamental factor in choosing gear oil. If the viscosity is too high, it can cause overheating of the friction surfaces and result in unnecessary power loss. Common steels used in manufacturing car gears include tempered steel, quenched steel, carburized and quenched steel, and nitrided steel. Cast steel has slightly lower strength than forged steel and is often used for larger gears; gray cast iron has poorer mechanical properties and can be used in lightly loaded open gear transmissions; ductile iron can partially replace steel in gear manufacturing; plastic gears are mostly used in lightly loaded applications where low noise is required, and they are typically paired with steel gears that have good thermal conductivity.