A friction modifier is a chemical additive that is used to reduce friction and wear. It is often used in engine lubricants and transmission fluids, especially to increase fuel efficiency.

When applied to a metal surface, the friction modifier molecules create a thin, cushioned film, which helps to prevent the surfaces from contacting. This film reduces friction, wear, and noise. These products also serve as anti-corrosion and anti-oxidation agents.

Friction modifiers are typically oil-soluble chemicals. These additives are typically used in engine oils, power steering fluids, and tractor fluids. They may interfere with other additives, and they can be formulated in various combinations to enhance their performance.

In order to achieve maximum effectiveness, the friction modifier must be selected to match the contact conditions. They also need to be adapted to higher temperatures. The type of friction modifier that works best for different situations depends on the opposing group.

Friction modifiers have positive or negative friction properties. Positive friction modifiers act as a lubricant, while negative friction modifiers have negative rubbing properties. Both types are effective, but they may be antagonistic to each other.

High positive friction modifiers leave a thin film on the wheel or rail. They can also be embedded in a polymeric matrix. Alternatively, they can be formed into a rectangular stick.

Some of the most common organic friction modifiers are carboxylic acid, phosphonic acid, and imide. They are usually diluted with synthetic base oil. Another option is to add friction modifiers directly to a lubricant.