Is it necessary to upgrade the free oil provided by Nissan?

No, the free oil provided by Nissan does not require upgrading and can be used as is.

Oil replacement cycle:

Mineral oil can be replaced at 5000 kilometers or 6 months, while semi-synthetic oil can be replaced at 7500 kilometers or 6 months, and fully synthetic oil can be replaced at 10000 kilometers or 12 months. It is unnecessary to replace the oil too early as it will result in waste and extend the replacement cycle, which may cause engine wear and increased carbon accumulation. On the other hand, the oil will also deteriorate with time.

Oil cleansing methods:

Alcohol can be used to clean the oil. The higher the alcohol concentration, the better. You can use a small amount of essence of peppermint oil on the clothes with oil stains, let it sit for a few seconds, and then wash it off. You can also use gasoline to clean the oil. First, apply some gasoline to the oil-stained area, and use kerosene and turpentine to clean the area once the oil has dissolved. Finally, use regular cleaning methods to wash it off. Engine oil, also known as engine lubricant, can serve as a lubricant, coolant, sealant, and protector of the engine.