What Color of Engine Oil Indicates It Needs to Be Changed?
2 Answers
Engine oil needs to be changed when it turns brown or black and is no longer translucent. Fresh engine oil typically appears light yellow, yellowish-brown, or dark brown and is translucent. Engine oil, also known as motor lubricant, serves multiple functions including lubrication and friction reduction, assisting in cooling, sealing to prevent leaks, rust and corrosion prevention, and shock absorption. Often referred to as the 'blood' of a car, engine oil is composed of base oil and additives. Its primary functions are to reduce friction and wear on moving parts, remove sludge and varnish from the engine, neutralize acids produced by fuel and lubricant oxidation, improve piston ring sealing, and cool the engine by carrying away heat from moving components.
I've been driving the family car for years and always check the oil color before changing it. When newly added, it's that transparent amber color, very clear and beautiful. After a few months or a few thousand kilometers, it gradually darkens, turning into a deep brown, which is a normal consumption process. But if the oil becomes pitch black and shiny like ink, or feels sticky with a gritty texture, then it's time to change it because it's saturated with dust and burnt residues. Once, I delayed changing it for too long, and the oil was so black I couldn't see the dipstick. As a result, the engine noise became louder, and the repair cost me several hundred dollars. So my experience is that color change combined with normal usage time (like checking every six months or 5,000 kilometers) is key—don't just rely on color, but also consider the actual condition. Make it a habit to regularly pop the hood and simply drip some oil onto a tissue. If it spreads slowly or has an unusual odor, take action immediately. This is a crucial step in keeping your car healthy.
