What Color of Engine Oil Indicates It Needs to Be Changed?

[CeciliaLee]

Here are the methods to determine when engine oil needs to be changed based on its color: 1. Freshly added engine oil is golden yellow in color. The detergents and dispersants typically added to the oil help clean off the carbon deposits and gum films adhering to the pistons, dispersing them in the oil to reduce engine deposits. 2. From this, we can understand why lubricating oil turns black after being used for a period of time. However, the oil at this stage hasn't necessarily deteriorated. To determine whether the lubricating oil has deteriorated or needs to be changed, you can assess the oil's viscosity. 3. The method involves placing a drop of oil on a test paper and observing the spread. If the edges of the spread are not clear, the oil is still usable. If a ring forms, the oil is still acceptable. If the ring is very distinct and the spread is minimal, it indicates that the oil needs to be changed.