What are the methods for testing engine oil quality?

[JaxsonAnn]

Testing method: Use slow qualitative test paper. Steps are as follows: 1. Take out the oil dipstick, drop a drop of oil from the dipstick onto the slow qualitative test paper, place the test paper horizontally, and let it stand for 24 hours. 2. Three rings will appear on the test paper. 3. Sediment ring: At the center of the spot is where coarse particle impurities in the oil accumulate. The color depth of the sediment ring can roughly indicate the degree of oil contamination. 4. Diffusion ring: The ring around the sediment ring is called the diffusion ring, which is the trace left by fine particle impurities suspended in the oil diffusing outward. The finer the particles, the farther they diffuse. The width of the diffusion ring and the uniformity of its color are important factors, indicating the dispersing ability of oil additives against contaminants. 5. Oil ring: The outer ring beyond the diffusion ring is the oil ring, with colors ranging from light yellow to brownish-red, indicating the degree of oil oxidation.