Engine lubricants are complex fluids. Today’s higher performing engine lubricants contain a carefully balanced formulation of base oils, advanced additives and A measure of a fluid's resistance to flow. A fluid with a higher viscosity flows less easily. modifiers, each performing very specific and vital functions.
To work as intended, each lubricant needs to be carefully formulated and tested to ensure it performs up to or beyond specific approval and performance requirements. The below gives an overview of the typical components in an engine lubricant, reinforcing the complexity involved in formulating as well as understanding the specific needs the lubricant needs to perform to.
The primary or underlying fluid, usually a refined petroleum fraction or a selected synthetic material, into which additives are blended to produce finished lubricants.
Let’s start with the base oil. The API. The primary oil and natural gas trade association in the United States. API operates a voluntary licensing and certification program that allows engine oil marketers to use the API Engine Oil Quality Marks if their products meet specific requirements. (American Petroleum Institute. The primary oil and natural gas trade association in the United States. API operates a voluntary licensing and certification program that allows engine oil marketers to use the API Engine Oil Quality Marks if their products meet specific requirements.) has categorized base oils into five categories and within each category, base oils have a wide range of different technical and performance characteristics. And while the base oil makes up the majority of a heavy duty engine lubricant (which typically fall within 60 to 95% of the weight), even the highest quality base oil alone cannot provide full protection against the effects of heat, the forces of shearing, the effects of wear particles, chemical and water dilution as well as corrosion.
When developing additive packages, formulators need to be aware of the specific base oil being used, as different additive formulations will be required according to the characteristics of each base oil.
Viscosity modifiers are polymers specifically designed to help control the viscosity (thickness) of a lubricant over a specified temperature range and operating environment. As engine components become more and more sophisticated, advanced polymers enable more efficient operation, in increasingly severe environments and are critical in providing maximum efficiency, durability and protection.
A wide range of A lubricant additive, usually a polymer, whose main function is to reduce the tendency of an oil's viscosity to change with temperature. Modern VMs are performance polymers that can provide additional benefits as well. technologies exists and the specific viscosity modifier required is dependent upon a number of interrelated factors including the operating conditions the overall lubricant needs to perform in, alongside the base oil and additives being used.
Although the additives make up a small part of the volume of the lubricant, they have a big role in protecting critical engine parts. The additive package can contain:
A substance added to a fuel or lubricant to keep engine parts clean. In motor oil formulations, the most commonly used detergents are metallic soaps with a reserve of basicity to neutralize acids formed during combustion.
An additive that helps keep solid engine oil contaminants in suspension, thus preventing the formation of sludge and varnish deposits on engine components. Dispersants are usually nonmetallic ("ashless") and are usually used in combination with detergents.
A lubricant additive that introduces a friction-reducing film between surfaces where mild sliding conditions occur. Friction modifiers are typically included in a performance additive package and can be used in some applications like automatic transmissions to encourage the interaction of moving components.
A lubricant additive that protects lubricated metal surfaces from chemical attack by water and other contaminants. Corrosion inhibitors are typically included in a performance additive package.
PPD. A lubricant additive that lowers the lowest point at which a lubricant flows so that the lubricant can be used in cold environments. PPDs are typically not included in a performance additive package.
All of those additives must be carefully balanced so that they work together to perform their specific functions. Lubrizol’s chemists have the expertise to create these complex formulations so that none of the additives, base oil and viscosity modifiers are in conflict with each other, and they all work in harmony so the lubricant performs as intended. Too much of one additive can prohibit the other additives and viscosity modifiers from doing their jobs. For example, if there is too little foam inhibitor, foam will form and the engine will cavitate, resulting in damage. Likewise, if the wrong type of detergents are used, the acids won’t neutralize. Dispersants won’t be able to keep the soot from agglomerating and depositing on engine parts. So, everything has to work together in precise harmony. And that’s where Lubrizol’s foundation of chemistry knowledge comes into its own. Our formulators know how to create additive packages to address everything from durability and protection requirements to fuel economy and efficiency benefits.
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