What physical properties does oil have?
1 Answer
Oil has a high viscosity, a high boiling point, and a low freezing point.
VISCOSITY
Viscosity measures the resistance to flow. Honey has a high viscosity and flows slowly. Water has a low viscosity and flows easily.
The hotter a fluid is, the easier is flows. The cooler it is, the more it resists flow.
A good lubricant must be fluid enough at low temperatures to reduce friction in an engine. It must also keep its viscosity at high temperatures so that it does not become so thin that it flows out of the engine.
A high viscosity enables the oil to provide a layer of fluid between the moving parts. This prevents them from having too much contact.
Because the lubricant is more “slippery” than the metal surfaces, it reduces friction. A reduction in friction leads to less wear on components, easier movement, and reduced energy needs of the system
LOW FREEZING POINT
A lubricant must not freeze solid. That would prevent movement altogether.
HIGH BOILING POINT
If the lubricant has a high boiling point, it will remain between the metal surfaces even at high operating temperatures.
It is easy to read, has the required information and some, in plain language are on this site: http://auto.howstuffworks.com/synthetic-motor-oil1.htm
