Question

Viscosity varies with the temperature and hence if a surface to be lubricated is normally at high temperature it should be supplied with oil of higher viscosity.

(a) True

(b) False

This question was posed to me by my college professor while I was bunking the class.

This is a very interesting question from Properties of Lubrication in section Engine Friction and Lubrication of IC Engine

Answer 1

The correct answer is:

(a) True

Viscosity indeed varies with temperature. If a surface to be lubricated is normally at high temperature, it should be supplied with oil of higher viscosity. Higher viscosity oils are better able to maintain a stable lubricant film under high temperatures, providing better protection against wear and reducing the risk of breakdown.