Is it necessary to upgrade Nissan's free engine oil?

[StMaximus]

Nissan's free engine oil does not need to be upgraded; using the free one is sufficient. Engine oil change intervals: Mineral oil can be changed every 5,000 kilometers or 6 months. Semi-synthetic oil can be changed every 7,500 kilometers or within 6 months. Fully synthetic oil can be changed every 10,000 kilometers or 12 months. Changing oil too early causes unnecessary waste, while extending the change interval can lead to early engine wear, increased carbon buildup, and oil oxidation over time. Methods for cleaning engine oil: Use alcohol for cleaning, as alcohol can dissolve both organic solvents and water—the higher the alcohol concentration, the better. Apply a small amount of medicated oil (like Tiger Balm) to the area stained with engine oil, wait a few seconds, then clean. Use gasoline for cleaning: first wipe with gasoline, and for heavier stains, use solvent or turpentine to wipe until the oil dissolves, then wash as usual. Engine oil, or motor lubricant, serves to lubricate and reduce friction, assist in cooling, seal against leaks, prevent rust and corrosion, and provide shock absorption for the engine.