What is the normal color of car engine oil?

[LePaislee]

Car engine oil is normally golden yellow in color. The following methods can be used to determine when engine oil needs to be changed based on its color: 1. When newly added, car engine oil appears golden yellow. The detergents and dispersants typically added to the oil help clean off the carbon deposits and sludge adhering to the pistons, dispersing them in the oil to reduce engine deposits. 2. Although the color of the lubricating oil will turn black after being used for a period of time, the oil may not have deteriorated yet. To determine whether the lubricating oil has deteriorated or needs to be changed, you can check the viscosity of the oil. 3. The method is to place a drop of oil on a test paper and observe the spreading area. If the edge of the spreading area is not clear, it means the oil can still be used; if a ring appears, it means the oil is still acceptable; if the ring is very obvious and the spreading is not significant, then it means the oil needs to be changed.