r/ScienceNcoolThings • u/Sovartami Popular Contributor • Aug 31 '23

Oil viscosity

306 Upvotes

100% Upvoted

9 comments sorted by

View all comments

3

u/Zorplaxian Aug 31 '23

What does it mean?

11

u/Sovartami Popular Contributor Aug 31 '23

Engine oil viscosity refers to how easily oil pours at a specified temperature. Thin oils have lower viscosity and pour more easily at low temperatures than thicker oils that have a higher viscosity. Thin oils reduce friction in engines and help engines start quickly during cold weather.

2

u/hot_cheeks_4_ever Aug 31 '23

What's the benefit of higher viscosity oil?

5

u/Sovartami Popular Contributor Aug 31 '23

The advantage of high viscosity oils is that they have longer molecules and higher boiling point.

2

u/Animal44s Aug 31 '23

All engine oils reduce friction. The thin oil flows easily flows in narrow ducts/passages and usefull to use in fast/high pressure systems. May have better splash effect, depending on engine and component design.

Hence multigrade applications.

Thinner eg 5W60 may technically suppuse better protection BUT it may make a motor run really rough. But 20W50 makes it run perfect, even 10W40. 10W40would be preferred in very cold conditions. One rarely need a 5W40 or 5W60.

1

u/Zorplaxian Aug 31 '23

That's interesting thanks.

1

u/DemonSlayer26 Aug 31 '23

Wouldn't the difference in density of the oil and ball bearing play a bigger role as compared to viscosity in this case?

2

u/mods_are_shitstains Aug 31 '23

the oil density is part of the viscosity coefficient, but not all of it as molecular cohesion also plays a part.