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

[DiStephanie]

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.