How to Identify the Quality of Engine Oil?

[MadisonMarie]

Methods to identify the quality of engine oil are as follows: 1. Observe the color of the oil: Domestic genuine bulk engine oil is mostly light blue with a bright luster and uniform flow. Imported engine oil is golden with a slight blue tint, crystal clear and transparent, with exquisitely crafted oil cans, clear and neat edges of patterns and codes, and no color leakage or overlapping; otherwise, it is counterfeit. 2. Smell the odor: Qualified engine oil should have no special odor, only a slight fragrance. Any engine oil that has a strong olfactory stimulation and abnormal odor is deteriorated or inferior oil and must not be used. 3. Oil drop test: Drop a drop of oil from the oil pan onto white paper. If the black spot in the center of the oil drop is large, black-brown, uniform, and free of particles, with a small yellow infiltration around it, it indicates that the oil has deteriorated and should be replaced. If the black spot in the center of the oil drop is small and light in color, with a larger yellow infiltration trace around it, it indicates that the oil can still be used.

[JuliannaMarie]

I've been driving for over a decade and mainly rely on experience and sensory checks to determine oil quality. Fresh engine oil has a golden color and is clear and transparent. Once it turns black or contains sediment, it indicates contamination or aging, resulting in poor lubrication. I dip my finger in to check viscosity: good oil feels slightly thick but not greasy, while overly thin oil may be inferior or adulterated. Smell is also important—genuine oil has a distinct chemical odor, unlike strange smells like a sewage ditch. Testing in the engine is simple: after adding oil, drive for a while and listen for noise. If there's excessive noise or unusual sounds, the oil isn't performing well. I always remind myself not to buy cheap knockoffs—only API-certified oil from reputable stores is reliable for protecting engine longevity. Changing the oil once a year during maintenance and keeping the oil level proper using the dipstick has helped me avoid major repairs.

[VanBrooke]

I just got my driver's license, and identifying engine oil is quite novel and practical for me. I learned a little trick online: put a drop of engine oil on a white tissue and let it spread slowly. Good oil will form a uniform ring with a light color in the center and clear edges; deteriorated oil will spread unevenly, with black spots or sludge. Another simple method is to smell it: genuine oil has a non-irritating odor, somewhat like fresh lubricating oil, but if it smells sour or burnt, change it immediately. Regularly check the dipstick before driving—if the oil level is low or the color has darkened, it’s time for a change. I remember that engine oil plays a big role in lubricating engine parts to prevent wear, and using poor-quality oil can shorten the car’s lifespan and cost more in the long run. Choose a reputable brand with SAE ratings on the bottle, and check the anti-counterfeiting code when shopping online.

[DelSebastian]

I have a slight interest in mechanics and use common professional tools to identify engine oil but keep it simple. Try the oil test paper: after dripping the oil, observe the diffusion pattern; good oil has fewer impurities and spreads evenly; aged oil shows a sediment ring or appears turbid. Viscosity testing is essential: pour the oil into a small cup, shake it, and observe the flow speed—if it flows too quickly, the viscosity is poor, and the protective power is weak. Certification is crucial—the bottle should have API and ILSAC seals. Test it on the engine: after adding the oil, let it idle for a few minutes; if the noise decreases, the effect is good. On a related note, engine oil also helps cool and clean the engine's interior; using fake oil may clog the oil passages and cause malfunctions. Before each oil change, read the instructions to match the vehicle model's specifications, saving effort and money.