Understanding the term ‘Motor Oil’
Have you ever wondered which oil is favorable for your automobile at various temperatures.
Some specific oils are better suited for varying engine temperatures.
Objective:
By the end of this post we hope to have learnt;
- The different oil grades
- Types of suited for oil for various temperatures
What is Motor Oil?
Motor oil or engine oil are substances that are made up of base oil, antiwater addictive (which prevents metal-to-metal contact between parts of gear), Dispersant or dispersing agent (which is typically a surfactant that is added to a suspension of solid or liquid to prevent their settling or clumping), Detergents and for multi-grade oils viscosity index improver.
What are motor oil used for?
They are employed for lubrication of moving parts. It neutralizes acids that emanate from fuel and from the oxidation of lubricants. It also cools the engine by transmitting heat away from running parts.
How is motor oil graded?
Motor oil are graded based on their viscosity qualities by the society of automotive engineer(SAE)which uses numerical code in evaluating of motor oils, for example SAE40 which are slim when heated.
Oil producers required to begin with thick oils, but it was problematic to kick-start the engine in cold conditions since it would not crank. Oil addictive was introduced that permitted oil thin out less quickly(i.e. retain a high viscosity index).
Different Types of Motor Oil Grades
You might see different grades for example you see SAE 15W-30, or SAE5W-40. Now there are two different values here. Let us understand what they mean.
So there is one set which tells us the oil performance in cold temperatures(0W, 5W, 10W, 15W, 20W, 25W, 30W, 40W, 50W, and 60W). The second value measures for a much higher temperature(8,12,16,20,30,40,50).
The higher the viscosity the higher the SAE code. Larger numbers are thicker.
The SAE has separate viscosity for gear and manual transmission oils.
How does each Motor oil grade work at different temperatures?
The value with the W represents how the oil functions in lower temperature while the second value after the W measures for a much higher.
For example, SAE15W-30. The oil acts as an SAE15 at cold temperatures(15W for winter) and like an SAE30 at 100 degrees.
Note: The W stands for winter.
The lubricant with a low viscosity grade the easier it is for the engine to start cold. They have more fluidity and more liquid will flow more easily but thicker ones will not flow under such condition.
Higher grades are suited for higher temperatures, which will flow well and help form a protective film across engine parts.
In low temperature it is better to choose an oil with low viscosity grade to facilitate oil movement in your car during cold engine start. They are less thick and therefore more fluid and require less work done by the oil during start up. So a 5W is better suited in lower temperature than a 15W.
Classical types of oil grades
Monograde oils: are oils that function over low temperature range. They have single grading for example either you see SAE15W or the SAE30.
They are used in older vehicles. During winter you use the one with the W and during higher temperatures you use the one without the letter W
Multigrade oils: are used in modern cars They are multi graded for example SAE15W-30. They are more temperature resistant.
Conclusion
I hope that now you can differentiate engine oils based on their grades.
