What Is SAE Oil?by Amber Arguijo
Most vehicle manufacturers recommend that owners change a car's oil every three to five months, which makes for a lot of oil consumption in the U.S. That level of consumption has spawned a large market for motor oil. The one thing all oils have in common is that they are SAE graded, but even that trait is sometimes a mystery.
What Does SAE Stand For?
SAE is an abbreviation for the Society of Automotive Engineers. The society was founded in 1905 by Andrew Riker and Henry Ford and continues to represent automotive engineers across the world.
What Is SAE Oil?
SAE oil is simply oil that has been evaluated by the Society of Automotive Engineers and assigned a number based on the results of several tests. The SAE developed a pattern of labeling oil, such as 5W-30 or 10W-40, which means that all oil carrying that label follows the SAE guidelines for that category.
How to Read the Oil Grades
The grades assigned by the SAE are formatted with a first number followed by a "W" and then a second number. The first number, along with the "W," signifies that the oil is suitable for winter use because it remains thin even in the cold. For example, 5W is suitable for use in temperatures as low as -25 degrees Celsius, 10W for temperatures as low as -20 degrees Celsius, 15W for -15 degrees Celsius and 20W for -10 degrees Celsius. A 0W oil was recently developed and is used primarily in workshops, given its higher price tag. However it is sometimes used in places such as Canada that have extremely harsh winters.
The second number indicates how the oil will perform in very hot temperatures---the goal is to keep the oil from getting too thin because thicker oil performs better in heat. These numbers range in multiples of 10 from 10 to 60, with 60 being the thickest.
Oil that is graded 5W-60 is the most versatile oil that is widely available. It has the highest resistance to thickening in the winter and the highest resistance to thinning in the summer.
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