What are the car engine oil additives？A glance at engine oil additives.

The commonly used additives for car engine oil include detergents, dispersants, anti-wear additives, Anti-oxidants & corrosion inhibitors, viscosity improvers, pour point depressants, rust inhibitors, and anti-foaming additives.

1. detergents & dispersants

The carbon particles, smoke, and dust in the air generated by fuel combustion will enter the engine oil, producing acidic substances in the high-temperature oxidation environment of the engine oil, ultimately forming carbon deposits, gums, and acidic substances that block the oil circuit, causing lubrication failure.
detergents and dispersants are used to remove carbon deposits on mechanical surfaces through solubilization, dispersion, acid neutralization, and detergence effects. Disperse and suspend them in the oil, and remove them through a filter. these deposit control additives account for approximately 50% of the total amount of engine oil additives.

 

2. antioxidant and anti-corrosion additives.

Even the most refined engine oil cannot avoid contact with air and corrosion of metals by oxides, so it is necessary to add antioxidant and anti-corrosion additives to the engine oil to prolong the engine oil's life.

 

3. viscosity index improver.

The viscosity index improver Improves the viscosity and temperature performance of engine oil, as we know, multi-stage engine oils have a viscosity index improver inside, which can be used throughout the year in different seasons.

 

4. pour point depressants.

The pour point depressants prevent the formation of a three-dimensional network structure that leads to oil solidification, reducing the oil pour point, and improving low-temperature fluidity.

 

5. Antifoaming additives.

When the crankcase is running at high speed, the foam will be formed under the action of strong vibration and stirring, increasing the contact surface between oil and air, which will lead to oxidation, shorten the service life, reduce the cooling effect, lead to overheating or even burning of parts, and increase wear. An anti-foaming additive is to prevent the formation of foam.

6. Oilness additives, anti-wear additives, and extreme pressure additives.

 

It is difficult to ensure liquid lubrication between the engine piston and cylinder wall, often operating under harsh boundary lubrication conditions. To reduce wear, these three additives are usually added to improve the oiliness and extreme pressure performance of the engine oil.

Oilness additives refer to additives that form physical or chemical adsorption films on metal surfaces under boundary lubrication conditions to reduce friction and enhance lubrication, also known as friction improvers. They include animal and vegetable oils, fatty acids, fatty acid esters, and sulfurized oils.

Extreme pressure additives refer to boundary lubrication under high temperatures and pressures, and this most stringent boundary lubrication is commonly referred to as extreme pressure lubrication. This additive can form a chemical reaction film on the metal surface to prevent local sintering on the friction surface. Compounds mainly containing active elements such as sulfur, phosphorus, and chlorine decompose and react with the metal friction surface at high friction temperatures, generating compounds with lower shear stress and melting point than metals. During the formation process, they flow to the surface around the contact point, making the surface smooth and playing a role in chemical polishing, The result is a decrease in the load per unit area.

 

7. rust inhibitors.

It is an oil-soluble surfactant that can protect metal surfaces and delay corrosion in 3 ways.

a. Form an adsorptive protective film on the metal surface.

b. Replace the water and droplets on the metal surface, remove water from the metal surface,

c. collect and disperse polar substances such as water and organic acids in oil, and dissolve them in micelles.