Question

A more viscous oil can carry a greater load, but it will offer great friction to sliding movement of the one bearing surface over the other.

(a) True

(b) False

I have been asked this question during an internship interview.

My question is taken from Properties of Lubrication topic in division Engine Friction and Lubrication of IC Engine

Answer 1

The correct answer is:

(a) True

A more viscous oil can indeed carry a greater load because it can form a thicker lubricating film between bearing surfaces. However, the trade-off is that it offers greater friction to the sliding movement of one bearing surface over another due to the increased resistance to flow. This can lead to higher frictional losses, especially at higher speeds or temperatures.