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

[McGavin]

Typically, the viscosity of the engine oil is used to determine whether it needs to be changed, rather than observing the color of the oil. Methods to determine if engine oil needs to be changed: Take a drop of oil and place it on a test paper. Observe the spread of the oil. If the edges of the spread are not clear, it means the oil can still be used. If a ring appears, it indicates the oil is still acceptable. If the ring is very distinct and the spread is minimal, it means the oil needs to be changed. Grade 1: There is no clear boundary between the deposit zone and the diffusion zone of the oil spot. The entire oil spot is uniform in color, and the oil ring is light and bright, indicating good oil quality. Grade 2: The deposit ring is dark in color, the diffusion ring is wide, and there is a clear boundary. The oil ring is yellow in varying shades, indicating the oil is contaminated but still usable. Grade 3: The deposit ring is dark black, deposits are dense, the diffusion ring is narrow, and the oil ring has darkened, indicating the oil has deteriorated. Grade 4: Only the central deposit ring and oil ring are present, with no diffusion ring. The deposit ring is pitch black, with dense and thick deposits that are difficult to dry. The oil ring is dark yellow or light brown, indicating the oil has oxidized and degraded. Method for changing engine oil: When adding engine oil, ensure the oil level is between the min and max marks on the dipstick. The oil level should not be below the min mark or above the max mark. If the oil level is below the min mark, it can lead to insufficient lubrication in the engine, increasing wear and tear. If the oil level is above the max mark, it can increase resistance during engine operation, leading to reduced power and increased fuel consumption. Always check the oil level carefully when adding oil.