What's the purpose of changing the engine oil and the oil filter?
the higher the level of the following, the viscosity of the oil is related to the environmental temperature you are using, for example, the smaller the number before the letter W 5W30, the stronger the low temperature flow.
Oil is currently on the market is divided into SJ/SM/SN several grades, S after the letter,
Replacement of oil is because the oil will be used with the oxidation, loss of lubrication, anti-corrosion and other functions, so you need regular replacement, and replace the oil filter is to filter out the oil in the particles, broken metal and other impurities.
