Oil needs to be thin enough to flow quickly on a cold start to provide immediate lubrication, but thick enough to maintain a film strength when the engine is hot and under stress. The number after the dash describes the oil's viscosity at the engine's normal operating temperature.
Understanding Motor Oil Heat Management and Viscosity for Engine Protection
Without this constant lubrication, the high temperatures and forces generated during combustion would cause rapid damage to the engine block and other critical components. High-performance engines, turbocharged engines, and extreme temperatures.
This is why motor oil is labeled with a code such as 5W-30 or 10W-40. The base oil, which makes up the majority of the product, provides the fundamental lubrication properties.
How Motor Oil Manages Heat to Protect Your Engine
These chemical compounds are mixed into the base oil to enhance its capabilities. Additionally, modern detergents and dispersants in the oil work to suspend dirt, varnish, and other byproducts of fuel combustion, keeping them suspended until they can be trapped by the oil filter.
More About What is motor oil
Looking at What is motor oil from another angle can help expand the discussion and give readers a second clear paragraph under the same section.
More perspective on What is motor oil can make the topic easier to follow by connecting earlier points with a few simple takeaways.
