Friction modifiers are additives added to motor oil to help improve fuel economy. While friction modifiers are typically found in engine oils, they are also used in ATFs.
Friction modifiers are designed to reduce the shear in the lubricant, thereby reducing the contact between engine parts. They are usually made from either synthetic or natural fatty acids. Some are even made from solid materials. These additives are designed to work with the specific performance of a vehicle.
The use of friction modifiers is a growing trend in engine lubricants. These additives are especially important in boundary lubrication conditions, where there is an increased number of components operating at the same time. Several recent tribology experiments have provided new insights into the behaviour of boundary lubrication systems.
Most engine oil formulations have been trending towards lower viscosity. This has led to the development of more robust friction modifiers that can withstand the pressures of low viscosity lubricants.
These products are used in automotive transmissions, as well as in gear changes. In general, they prevent friction between engine parts, which reduces wear. However, they are prone to shearing down and detonation.
There are several different types of friction modifiers available, and each one acts differently under different shear conditions. Some extreme pressure additives include zinc dithiocarbamate and molybdenum dithiocarbamate.
These chemicals have a slight molecular attraction to metal surfaces. As the temperature increases, they activate. When they are used in engine oils, they are deposited at the piston ring-cylinder wall interface.