Which characteristic of engine oil does viscosity measure?

Which characteristic of engine oil does viscosity measure?

• A. Color
• B. Ability to flow
• C. Density
• D. Temperature stability

Answer: (B)

Viscosity is a measure of how easily a liquid flows, i.e., its resistance to flow. For engine oil, this describes how thick the oil is and how readily it moves under pressure and at operating temperatures. A high-viscosity oil is thicker and flows more slowly, forming a thicker lubricating film; a low-viscosity oil flows more easily and forms a thinner film. Color, density, and temperature stability aren’t describing flow behavior: color has no relation to flow, density is about mass per volume, and temperature stability concerns how viscosity changes with temperature, not the basic flow property itself. So viscosity measures the oil’s ability to flow.

Viscosity is a measure of how easily a liquid flows, i.e., its resistance to flow. For engine oil, this describes how thick the oil is and how readily it moves under pressure and at operating temperatures. A high-viscosity oil is thicker and flows more slowly, forming a thicker lubricating film; a low-viscosity oil flows more easily and forms a thinner film. Color, density, and temperature stability aren’t describing flow behavior: color has no relation to flow, density is about mass per volume, and temperature stability concerns how viscosity changes with temperature, not the basic flow property itself. So viscosity measures the oil’s ability to flow.