A wide range of additives are available to be selected by a formulator for a specific lubricant application. In some cases, there is a need to work with a large number of additives because the operating conditions are complex. One example is a metalworking fluid where each usage is unique, and issues such as microbial contamination, hard water and foaming must be dealt with in addition to the fluid having the necessary components to perform the machining operation. 

In today’s challenging competitive environment, formulators do not always have the time to carefully develop a specific lubricant for a particular application. Multifunctional additives and additive packages may then be an option to assist in reducing development time and helping formulators work with additives that can provide several beneficial characteristics to their products. 

An added factor is using the right base stock with a specific multifunctional additive or additive package. The base stock may impart the needed solvency and elastomer compatibility to enable the multifunctional additive to provide the benefits needed for the lubricant to accomplish its task.

This article provides input from the following individuals on multifunctional additives and additive packages that spans automotive and industrial applications. 

1. Gerardo Alvarez, Afton Chemical
2. Dr. Michael Driver, Chevron Oronite
3. Dr. Pritesh Patel, Chevron Oronite
4. Dr. Justin Langston, Evonik Oil Additives USA
5. Dr. Erik Willett, Functional Products Inc.
6. Jim Grabarz, King Industries
7. Dr. Annette Loos, LANXESS Corp.
8. Dr. Steffen Sandhöfner, LANXESS Corp.
9. Dr. Gareth Fish, Lubrizol 
10. Glenn Mazzamaro, Vanderbilt Chemicals

Definition of a multifunctional additive
STLE member Dr. Erik Willett, president of Functional Products Inc. in Macedonia, Ohio, makes an analogy of additives to the positions on a U.S. baseball team. He says, “Each of the players on a baseball team have a position that performs different tasks whether the individual is in the infield, outfield or is the designated hitter. These functions can have an individual fielding a specific position or hitting from a specific side of home plate. Multifunctionality comes into play when the individual hits from both sides of home plate, which is known as switch hitting.”

Willett continues, “A multifunctional additive is one raw material in the formulation which has the function of improving several properties. Examples may include providing antiwear, mild extreme pressure (EP) and some antioxidant performance as well as acting synergistically when used in combination with other components.”

STLE Fellow and Certified Lubrication Specialist™ (CLS) Dr. Gareth Fish, Technical Fellow at Lubrizol in Wickliffe, Ohio, says, “The classic example of a multifunctional additive is zinc dithiophosphates (ZnDTP). According to Hugh Spikes,¹ this additive type was developed in the 1940s and functions as antioxidants and antiwear additives. Most of the metal dithiophosphates function as antioxidants in addition to offering antiwear. Other additives perform different multifunctional roles such as dithiocarbamates (DTC, antioxidant and enhanced load carrying), and amine phosphates (act as antiwear additives and rust inhibitors).”

STLE member Dr. Justin Langston, technical service department manager, Lubricant Additives, for Evonik Oil Additives USA in Allentown, Pa., cites the publication, “Lubricant Additives” edited by Rudnick.² He says, “Multifunctional additives are defined as those that ‘combined properties of antioxidancy, antiwear and to some extent dispersancy.’ But today’s formulators require additives that can exhibit more than these three areas to meet the demands of modern equipment. Multifunctional additives are needed to assist formulators with developing products that promote performance, efficiency and durability.”

Dr. Annette Loos, application technologist for LANXESS Corp. in Mannheim, Germany, says, “Lubricant additives typically serve one primary function per substance, but they often exhibit beneficial secondary properties. However, addressing more complex requirements necessitates a carefully balanced combination of multiple active ingredients, as no single additive can cover all needs.”

Dr. Michael Driver, manager, component development and fundamentals for Chevron Oronite in Richmond, Calif., says, “A multifunctional additive for lubricants is a chemical component or ingredient that not only performs its primary function but also offers additional performance benefits. For example, if an additive component’s main purpose is to reduce friction, it might also help prevent corrosion or improve wear performance. One other example includes a component that provides both cleanliness performance and contains a basic functionality that neutralizes acids during combustion. Use of a multifunctional additive may reduce or eliminate the need for other additives required to perform additional functions.”

STLE member Jim Grabarz, sales and product manager for King Industries in Norwalk, Conn., says, “A multifunctional lubricant additive is a chemical component that is added to a base fluid or grease used to enhance performance and/or chemical/physical properties simultaneously. In some cases, multifunctional additives are blends of specific chemical components that improve multiple lubricant properties.”

Gerardo Alvarez, marketing director – Americas for Afton Chemical in Richmond, Va., says, “A multifunctional additive is a single chemical component that delivers more than one performance benefit to a lubricant formulation. A good example of a multifunctional additive is a ZnDTP molecule. It provides both antiwear protection and oxidation inhibition in many lubricant formulations. Another example is a molybdenum-based additive, which delivers friction modification benefits while also contributing to oxidation protection.”

STLE member Glenn Mazzamaro, vice president, petroleum additives, for Vanderbilt Chemicals in Norwalk, Conn., says, “A multifunctional additive is a component that performs more than one performance function, e.g., antioxidant, antiwear agent, friction modifier, corrosion inhibitor, etc.”

Additive package
Grabarz considers a lubricant additive package to be a blend of chemical substances added to base oils or greases to enhance their performance and properties. He says, “Additive packages are used because they have already been tailored to contain a well-balanced composition of individual additives needed for different functions crucial to specific applications.”

Alvarez states that a lubricant additive package is a blend of multiple additive components, each contributing one or more specific performance attributes. Together they deliver the desired overall performance characteristics to the finished lubricant. He adds, “In the lubricant industry, each additive component is often referred to by its specific function—for example, detergents, dispersants, rust inhibitor, demulsifier, emulsifier, friction modifier and antioxidant. A lubricant additive package is carefully formulated to remain stable in solution over time, ensuring that all components work synergistically, and avoid negative interaction while delivering the intended performance in the finished lubricant.”

An additive package is a stable blend of several additive components which, when blended into an appropriate base oil or base oil blend, meets the performance requirements of certain general industry lubricant specifications and/or specific original equipment manufacturer (OEM) specifications, according to Mazzamaro. He says, “These additive components can be multifunctional or not. Multifunctional additive components may help to reduce the overall formulation cost.”

Dr. Pritesh Patel, manager, senior manager, global automotive/viscosity modifier/small engine technology for Chevron Oronite, indicates that selection of an additive package is dependent upon the desired applications and specified requirement of the lubricant for a particular application. He says, “Engine oils are a good example because they must meet diverse performance requirements determined by industry specifications such as ILSAC GF-7 for passenger car lubricants and the corresponding CK-4 specification for heavy duty applications. Often an OEM imposes additional performance criteria in the form of specific engine, rig or bench tests for their own equipment to help ensure the best performance of the lubricant.”

Patel continues, “If the additive package can meet the basic requirements, and simultaneously exceed performance in certain areas, it can be considered meeting multifunctional requirements. Essentially, this means the package not only performs its primary function but also provides additional benefits, making it more effective.”

Dr. Fish gives an example of an additive package that offers multifunctional benefits. He says, “A simple industrial circulating oil contains an additive package consisting of an antioxidant and a rust inhibitor. Such a package will be described as an R&O (rust and oxidation) offering protection against both degradation mechanisms.”

Dr. Fish cites the functions of components typically used in crankcase engine oils. He says, “Overbased detergents are needed to neutralize combustion acids and keep pistons clean, dispersants control soot, an antioxidant(s) prevents degradation and antiwear additives reduce wear in components such a piston rings, and liners and valve train components.”

Langston says, “Formulators of additive packages take special care to balance antagonistic and synergistic effects so that lubricant formulations can meet performance requirements set by industry standards, and OEM specifications. These standards usually cover many areas of performance including, for example, drain intervals, equipment protection, productivity and efficiency.”

Dr. Steffen Sandhöfner, senior manager applications technology for LANXESS Corp. in Mannheim, Germany, indicates that additive packages can shorten the product development process for formulators. He says, “Each industrial lubricant application has specific mechanical and chemical requirements. To offer customized solutions, formulators can use a specific additive package to minimize development time that meets the multifunctional solutions required for a specific lubricant application.”

Willett characterizes an additive package as a distillation of different additives that are found to be useful when used in certain combinations and are able to be put into one concentrate. He says, “The preparation of an additive package enables the raw material supplier to do the homework and in-depth technical testing that will validate its performance across a wide range of formulation types. This makes it more convenient for small or mid-sized formulators to spend extra time or expense in using the additive package to meet their specific needs. The result is the formulator can benefit from an accelerated development cycle that mitigates much of the risk (i.e., wasted time and research and design [R&D] costs).”

Determination of multifunctionality
Dr. Fish uses the example of a commercial vehicle or passenger car engine oil to indicate that multiple tests must be conducted to verify the multifunctionality of an additive package. He says, “Industry standardized tests that look at valve train wear, piston cleanliness, rust, corrosion and other salient features of a specific engine oil specification must be carried out. No single additive can pass all of these requirements. A skilled formulator would look at the requirements of the specification and application and, coupled with the viscometrics of the lubricant, put together a multifunctional package to meet the requirements.”

For an EP lubricating grease, Dr. Fish contends that besides evaluating basic grease characteristics such as rust and corrosion protection, wear and load carrying testing will need to be done to ensure that the lubricant has multifunctional characteristics.”

Willett cautions that many of the available additives used to boost lubricant performance are surface active and will compete with each other to determine which specific one is most effective. He says, “If only one type of additive is at the surface, then it truly must be providing performance in multiple areas of wear and corrosion by itself to perform competitively. If not, this monofunctional component will hinder the proper use of other components in the formulation and lead to failure in one or more areas of performance.”

Willett also maintains that while multifunctionality can be beneficial, it is not always desirable. He explains, “Sometimes a formulation under specific circumstances or with a non-standard base fluid may require a light touch-up on foaming or corrosion. In those cases, the most useful additive is one that can be added tactically without affecting the other properties of the formulation.”

An example in determining if a specific additive combination is multifunctional originates from a study using a modification of the four-ball wear procedure (ASTM D4172). A series of potential additives (E, B, M and S) were evaluated to determine if they can display both low wear and low coefficient of friction with the results shown in Figure 1. Willett says, “When used with base oil, all of the additives exhibit good antiwear characteristics, but none of them acted as a friction modifier. Unexpectedly, we found that synergistic combinations of additives S and two variations of E (E1 and E2) achieved breakthrough performance as friction modifiers while not impacting their ability to reduce wear.”


Figure 1. A modified four-ball wear procedure determined that synergistic combinations of additives S and two variations of E (E1 and E2) functioned not only to reduce wear but as friction modifiers. Figure courtesy of Functional Products.

Driver states that an understanding of an additive’s chemistry structure-property relationships, test performance and final application knowledge for a finished lubricant need to be determined to better understand if the specific component is multifunctional. He says, “In general, if an additive shows multiple functional properties and performance that reduces or eliminates the need for additional components in a formulation, it is deemed multifunctional. For example, let’s hypothetically develop a new additive designated as Additive A” to replace Additive A. By conducting testing, Additive A” is found to reduce the amount of another additive, Additive B, in a formulation. Assuming Additive A” and B perform different functions; this observation suggests that Additive A” exhibits multifunctional properties.”

Patel states that selecting a multifunctional component for an additive package or finished lubricant is part of a formation design and development. 

Besides testing, Grabarz reveals that identification of a multifunctional additive can be done by reviewing the product description and its intended applications. He says, “Examine the list of benefits of using a particular additive and look for terms such as multifunctional, package, or blend. If the description lists several benefits, such as antiwear, anticorrosion, antioxidant, etc., then this implies the additive is multifunctional.”

Mazzamaro suggests evaluating the additive in an appropriate formulation environment using accepted ASTM laboratory methods. He says, “Multifunctionality is apparent if the additive demonstrates positive activity in more than one type of test, e.g., oxidation, wear, friction, corrosion, deposit control, etc.”

Alvarez gives another example of a multifunctional additive that can deliver three distinct benefits to a lubricant. He says, “A dispersant viscosity index improver (VII) not only increases the lubricant’s viscosity index but also acts as a dispersant, helping keep surfaces clean by suspending oxidative deposits. Additionally, the chemical structure of this specific dispersant VII influences the lubricant’s frictional behavior.”

Loos believes that it is challenging for a single additive to exhibit more than one function such as displaying a combination of several characteristics such as antiwear, corrosion inhibition, antioxidant. EP, antifoaming and pour point depression. She says, “An additive package that combines multiple additives is a desirable option to ensure comprehensive protection and performance enhancement covering all required functions needed for a lubricant in a specific application.”

Lubricant applications needing multifunctional additives and packages
Langston states that driveline lubricants represent one application where multifunctional additives can provide more than one beneficial characteristic. He says, “Additives are available that impart both shear-stable thickening and excellent low temperature performance to driveline lubricants. Use of a VII in the right application can lead to dispersancy and solvency benefits.”

Langston also points out that the right type of high-viscosity base stock with balanced solvency will promote additive stability and elastomer compatibility. He says, “This base stock has a dispersancy functionality that contributes to a favorable frictional profile and a reduction of sludge and varnish.”

Alvarez discusses additives for passenger car motor oil (PCMO) applications, where the demands of modern engines call for multifunctional additive technology. He explains, “Performance in PCMO formulations for modern engines requires exceptional oxidative control to prevent deposits and sludge formation over extended oil drain intervals in harsh conditions. As mentioned earlier, ZnDTP, used for wear protection, and molybdenum, used for friction modification, along with supplemental oxidation inhibitors, all contribute to the lubricant’s overall oxidation stability.”

Examples of applications that require multifunctional additives include automotive and marine engine oils, industrial gear oils and hydraulic fluids, according to Driver. He says, “Multifunctional additives allow the development of more efficient lubricant formulations for wider applications, enabling formulators to simplify and potentially improve for most lubricant applications.”

Driver cites the benefit of multifunctional additives that reduce friction in an engine to improve fuel economy while also acting as antioxidants to protect the lubricant from the harsh operating environment. This dual benefit reduces the overall number of additives needed in a formulation.

Antioxidants factor into two examples of how they work in a multifunctional capacity with other additives. In Figure 2, a study demonstrates how combining a dispersant component (DISP) with an antioxidant (AO) leads to a significant reduction in deposit formation. The conclusion is the antioxidant not only fulfills its primary function but also acts in aiding deposit formation control.


Figure 2. Combining a dispersant component (DISP) with an antioxidant (AO) aids in deposit formation control while also limiting oxidation.³ Figure courtesy of Chevron Oronite.

A second example demonstrates how combining an antioxidant with certain dispersants can lead to an increase in the lubricant’s resistance to oxidation (see Figure 3). This case illustrates the ability of certain dispersants to also act as antioxidants in addition to their primary role.


Figure 3. Oxidation resistance can be increased in this study by combining an antioxidant with certain dispersants. The study indicates that dispersants fulfill their original function but also can act as antioxidants.³ Figure courtesy of Chevron Oronite.

Both figures are taken from a study presented at the 2025 STLE Annual Meeting.³

Overall reduction of formulation costs in most lubricant applications is a key driver for using multifunctional additives. Mazzamaro says, “Multifunctional additives are helpful in lubricant formulations where cost is an important issue, since they help reduce overall formulation costs.”

Grabarz indicates that multifunctional additives and additive packages are useful in a wide range of lubricant applications. He provides details on benefits and specific examples, “Use of multifunctional additive components has the advantage of being able to down treat certain additives resulting in less surface competition between additives leading to better overall performance. For example, inclusion of an amine phosphate in a formulation affords both antiwear and rust protection properties, eliminating the need for two different additives. Similarly, a synthetic metal sulfonate contributes excellent rust protection and demulsification properties eliminating the need for supplemental demulsifiers.”

Grabarz continues, “As mentioned earlier, selection of certain base fluids also can impart multifunctional properties. Alkylated naphthalene base stock can be used as a multifunctional additive when incorporated into a formulation, typically at 10%-60%, to impart multiple properties. These include improved thermal and thermos-oxidative stability, enhanced additive, solubility and response, improved seal swell, decreased volatility and improved varnish control for system cleanliness.”

Sandhöfner says, “Additive packages are most useful in applications where OEM specifications are mandatory. These applications include engines, hydraulics, turbines, gears and transmission systems. The use of optimized additive packages simplifies formulation and supply chain efforts, significantly reducing the development time for Tier 1 suppliers to OEMs.”

Dr. Fish indicates that multifunctional additives are needed in almost every piece of industrial machinery that utilizes oils and greases. He says, “The reason is lubricants need to impart rust prevention, copper passivation, enhanced load carrying and wear protection. Industrial gear oils and hydraulic fluids also must inhibit foam and aeration that can damage the equipment if allowed to happen. Some industrial fluids are also required to shed water through the use of a demulsifier, and others are required to emulsify any water contamination. These effects are added to the lubricant’s properties by the use of additives, but it is also essential that formulations are balanced so the demulsifier does not interfere with air release.”

Willett emphasizes economics and regulations in justifying the strong need for using multifunctional additives and/or additive packages. He says, “In highly competitive markets, there is always a need to streamline raw materials into fewer components to provide the best economy of scale and lowest added expense. Treat rates for individual components are typically in the 0.1%-1.0% by weight range for individual functions such as antiwear. Adding up the number of components needed for contributing at least six functions can prompt a formulator to have potentially 6% additives by weight in a lubricant.”

Willett continues, “Finding additives that can provide multiple functions is critically important in environmentally acceptable lubricants that are prepared to meet the EU Ecolabel certification program. Formulators are given a limited allowance of chemistry by weight percent to use in their products, so every fraction of a percent counts.”

Examples of multifunctional additives
Additives based on molybdenum chemistry exhibit multifunctionality, according to Mazzamaro, because they enhance control of oxidation, wear, friction and deposits. A 160,000-kilometer (100,000 mile) engine oil trial was conducted in a U.S. city with taxis. The incumbent lubricant, a GF-5 oil, contained 700 ppm phosphorus and 100 ppm molybdenum and displayed piston scuffing on the left side of Figure 4. When the additive balance was changed to 700 ppm molybdenum and 250 ppm phosphorus in an experimental engine oil, an improvement in piston scuffing is seen on the right side of Figure 4.


Figure 4. Piston scuffing seen in the left image is reduced by changing the additive balance to contain a higher treat rate of a molybdenum component (see the right image). Figure courtesy of Vanderbilt Chemicals.

The multifunctionality of molybdenum was further demonstrated in Sequence X timing chain wear test results found in Figure 5. Timing chain wear has been found to occur in turbocharged engines. Increasing the molybdenum content from 100 ppm (in the oil with the blue line results) to 750 ppm (in the oil with the red line results) leads to a significant decrease in timing chain wear over the 100-hour test period. In the higher molybdenum containing experimental fluid, the molybdenum combined with 252 ppm of phosphorus and 280 ppm of boron to achieve this result.


Figure 5. Increasing the treat rate of a molybdenum component in an engine oil led to a significant decline in timing chain wear (blue line versus red line) over a 100-hour test period. Figure courtesy of Vanderbilt Chemicals.

Grabarz provides the following list of multifunctional additives and the properties they display.

• Synthetic metal sulfonates. These additives provide excellent rust protection, impart excellent filtration and demulsification properties to overcome the negative effects of other additives, including zinc dithiophosphates and phenates.
• Dibutylthiocarbamate. Antiwear protection and secondary antioxidation properties are displayed by this additive.
• Tolyltriazole. Beside providing yellow metal protection, antioxidation performance can be boosted by preventing the formation of catalytic copper ions.
• Dimercaptothiadiazole derivatives. Yellow metal protection is also furnished by this additive. Multifunctionality comes from evidence of EP performance at higher treat levels.

An example of a calcium sulfonate derivative providing multifunctional additive is found in its use in a common HF-0 type hydraulic formulation using an ISO VG 46 (Group II) base oil. The additive based on a calcium naphthalene sulfonate/carboxylate complex demonstrates improved ferrous corrosion, demulsification and filtration properties as shown in Table 1.


Table 1. Introduction of an additive based on a calcium naphthalene sulfonate/carboxylate complex to a HF-0 type hydraulic formulation leads to improved ferrous corrosion, demulsification and filtration properties. Table courtesy of King Industries.

Two examples of multifunctional additives furnished by Willett are ZnDTP and polymethacrylate viscosity modifiers. He says, “ZnDTP is the classic example of a do-it-all chemistry providing varying levels of protection against wear, EP scuffing and oxidation. Ashless replacement technologies such as carbamates and amine phosphates also display similar characteristics.”

Willett continues, “Polymethacrylate viscosity modifiers are unique in the viscosity modifier world because they are able to provide viscosity plus the added benefit of wax suppression and pour point improvement. This is a more premium additive, but it saves the formulator the added cost of adding 0.1%-0.3% by weight of a separate pour point depressant in their high VII formula.”

Dr. Fish gives the example of automatic transmission fluids (ATFs) as using complex packages that provide multifunctional properties. He says, “ATFs need complex packages to allow them to work across a range of conditions from zero to high speed and from temperatures ranging from -40°C to +150°C. In addition to the usual lubricant properties needed, friction properties are of the highest importance to ATFs. These need to be maintained across a wide range of speeds, loads and temperatures. The result is an ATF fluid having a multifunctional additive package containing up to 30 different components to achieve the desired performance.”

Alvarez offers further insight into the complexity of formulating an additive package for ATFs. He explains, “Automatic transmissions, including planetary automatics, continuously variable transmissions (CVTs), and dual-clutch transmissions (DCTs), require carefully engineered multifunctional additive systems. These additives work synergistically within a single package delivering a broad range of critical performance attributes. Automatic transmissions are intricate systems composed of numerous moving parts and gearsets that demand robust protection against various forms of wear. The specific architecture of each transmission type also imposes unique friction modification requirements, particularly for torque converters and clutch assemblies, to ensure smooth and reliable power transfer. The same ATF must also serve as a hydraulic fluid. It must protect metal surfaces from corrosion, provide wear protection, foam and aeration control, flow consistently at low temperatures, protect seals, provide thorough lubrication, dissipate heat and prevent surface deposit formation. Balancing all of these demands in a single formulation presents a significant technical challenge that requires deep formulation expertise, and precise additive selection.”

With the renewed focus on emulsion retention in passenger car engine oil properties, Langston believes that alkyl methacrylate copolymers are an attractive multifunctional additive due to their ability to act as VII, dispersants, film-formers and pour point depressants. 

Loos indicates that multifunctional additive packages can be tailored to meet the specific requirements of different applications. She says, “The reason for using additive packages is that they combine various components (antiwear, corrosion inhibitors, antioxidants, EP agents, VII and antifoam agents and pour point depressants) that can be designed for the unique needs of specific lubricant applications.”

Two examples of multifunctional additives given by Patel are detergents and dispersants. Details on their properties are provided below.

• Detergents such as phenates, sulfonates and carboxylates provide cleanliness (protection against deposits) and also neutralize acids formed in engine oils during the combustion process.
• Dispersants based on polyisobutylene backbones contribute dispersancy against soot and sludge, while also exhibiting basic properties needed to neutralize acids.

Effectiveness of multifunctional additives
Grabarz feels that multifunctional additives are generally considered to be more effective and versatile than multiple monofunctional additives because they address multiple issues with a single product. He explains, “Multifunctional additives are often more efficient, allowing a formulator to achieve multiple formulation goals with a single product, reducing the need for multiple additives. These benefits bring cost savings by reducing the number of required additives and manufacturing complexity, so formulations can be more cost-effective.”

Grabarz continues, “In contrast, monofunctional additives are designed to address a single issue. They do not provide the benefits of other additive types, so formulations may require the use of multiple products to address a broader range of issues, driving up complexity and cost. Often using many monofunctional additives increases the likelihood of additive incompatibilities, which may form drop out or shorten a formulation’s lifespan.”

Willett says, “The goal for an additive package is to present formulators a unique and proprietary combination of additives, which work better than the sum of their parts, where 1 + 1 = 3. Not all combinations of two or three components provide a synergy. Often the mechanism of how multiple components function will lead to antagonistic effects like excessive corrosion, foaming or friction. Using a package will often have higher potential to outperform a monofunctional additive because there are more dials to turn and levers to pull behind the scenes. But there is also added complexity to balance chemistries properly, and to sourcing more raw materials as global logistics continue to become more complicated.”

Langston discusses an operational benefit for using multifunctional additives and additive packages but also cautions that using a package with a specific component could lead to inferior lubricant performance. He says, “Advantages in operations and logistics can be realized in using multifunctional additives because lubricant blending plants end up managing a smaller number of components. But performance compromises could take place in specific situations. For example, inclusion of pour point depressants in additive packages may limit a formulator’s ability to optimize the treat rate for a broader range of base stock slates and, in some cases, could lead to reduced low temperature performance.”

Alvarez highlights the advantages of using multifunctional additives and additive packages to reduce formulation complexity, as opposed to blending lubricants from individual additive components. He explains, “A multifunctional additive or the use of well-designed additive packages deliver multiple performance benefits within the lubricant, simplifying the formulation while ensuring compatibility and performance balance across critical properties such as wear protection, oxidation stability, detergency and friction control.”

Two benefits mentioned by Sandhöfner are the use of multifunctional additive packages can allow formulators to easily prepare lubricants on a regional basis and ease of obtaining OEM approvals. He says, “Regionally, customers only need to select the appropriate base stock and can then add the appropriate multifunctional additive package to prepare a high-performance lubricant. Additionally, under certain conditions, OEM approvals can be obtained, providing end-users with enhanced security regarding lubricant compatibility.”

Driver explains that certain additive chemistries can contribute more than one function to a lubricant formulation. He says, “Some phosphorus and sulfur-based additives can deliver both wear and oxidation protection. Another well-known example is molybdenum-based additives that can reduce both wear and friction while also boosting oxidation inhibition by acting synergistically with amine-based antioxidants.”

Additive categories with specific needs
Alvarez notes that formulating multifunctional additive packages requires significant expertise from experienced companies. He explains, “Combining components such as detergents, dispersants, antioxidants, antiwear additives, friction modifiers, EP agents, foam control, corrosion inhibitors, antioxidants, seal conditioners, friction modifiers, rust inhibitors and others for use in applications such as automotive and industrial gear oils, engine oils, ATF and hydraulic fluids involves a delicate formulation balance. Each component must not only perform its intended function but also remain compatible with other components to ensure overall system stability, and optimized performance.”

Grabarz mentions greases and industrial lubricants as applications with specific needs for better multifunctional additives. He says, “For greases, additives that can provide better protection against wear and tear on moving parts, protect under high loads and temperatures where EP agents are needed, protect various metal parts against corrosion and act as antioxidants to prevent grease thickening and degradation are needed.”

Grabarz continues, “Better multifunctional additive options are needed for industrial lubricants used in various machinery and equipment to reduce friction, wear and heat generation. In particular, additives for use in hydraulic and compressor fluids are needed to better control corrosion and deliver demulsification properties.”

Willett encourages the greater use of dispersant viscosity modifiers in multigrade engine oils and hydraulic fluids. He says, “Besides providing viscosity control and dispersancy, dispersant viscosity modifiers contribute additional benefits compared to polyisobutylenesuccinic anhydride dispersants because their larger size allows them to encompass abrasive wear particles and prevent scratching of lubricated surfaces.”

On the matter of grease, Willett indicates that specialized polymers can be melted into greases to provide a wide range of benefits at low treat rates including reduction in oil bleed, improved yield, improved water resistance and better adhesion to moving equipment. He adds, “These benefits provide an easy way to upgrade a standard product while keeping the vast majority of the bill of materials the same.”

Patel lists four additives where improvements are needed.

• Antiwear additives. A general preference is requested by formulators for antiwear additives that specifically exhibit low or reduced phosphorus levels, provide or replace wear performance from traditional ZnDTP additives and also protect against oxidation and corrosion.
• Dispersants. Better multifunctional dispersants are needed to help reduce overall treat rates and cost, while maximizing performance benefits that simultaneously improve sludge and soot control along with cleanliness under harsh conditions.
• VII. Besides providing viscosity index improvement, there is an increasing need for traditional VII to aid in reducing deposits, enhancing fuel economy and dispersancy.
• Detergents. With end-users dealing with higher equipment operating temperatures, more efficient detergents are required to handle deposits formed under these operating conditions while also providing basicity to neutralize acids.

Mazzamaro argues that all lubricant applications will benefit from using multifunctional additives. He says, “They help to simplify formulations and can reduce costs by reducing blending steps, and the number of additives needed in inventory.”

Future use
Dr. Fish cautions that future use of multifunctional additives may decline due to regulatory concerns. He says, “Single property additives are growing and will become more important with REACH restricting several multi-use additives. For example, if ZnDTP gets restricted or authorized for only specific uses, then formulators would have to use separate antiwear and antioxidant additives to replace it.⁴ 

Table 2 provides an example of an antioxidant study using a conventional lithium 12-hydroxystearate soap thickened API Group I base oil with a kinematic viscosity of approximately 150 cSt at 40°C.⁴ Six antioxidants used separately or in combination were evaluated in the base grease for oxidation induction time (OIT) measured in minutes at 180°C. The procedure used was ASTM D6138 using pressure differential scanning calorimetry (PDSC). 


Table 2. The oxidation resistance of a conventional lithium 12-hydroxy stearate soap thickened API Group I base oil was evaluated for oxidation induction time (OIT). Six antioxidants (DTBP = di-t-butyl phenol, BHT = di-t-butylhydroxytoluene, sDPA = alkyl substituted diphenylamine, zinc 1 = primary zinc dialkyldithiophosphate, zinc 2 = secondary zinc dialkyldithiophosphate and TMHQ = polymerized 1,2-dihydro-2,2,4-trimethylquinoline) were added to the base grease, and the results were reported in minutes. The test was run using ASTM D6138. A combination of two antioxidants (TMHQ + sDPA) was needed to provide comparable performance to a primary or secondary ZnDTP. Table courtesy of Lubrizol.

A combination of two antioxidants (Polymerized 1,2-dihydro-2,2,4-trimethylquinoline [TMHQ] + Alkyl substituted diphenylamine [sDPA]) was needed to provide comparable performance to either a primary or secondary ZnDTP. Fish says, “This study demonstrates that the combination of two single property additives (in this case, antioxidants) was needed to replace a multifunctional additive, ZnDTP.”

Mazzamaro continues to see the need for multifunctional additives. He says, “As performance requirements become more challenging, multifunctional additives are a great tool in the formulators toolbox to enhance performance of an existing formulation.”

Loos predicts that multifunctional additives will be needed in industrial applications such as industrial gear oils, metalworking fluids and hydraulic systems. She says, “Hydraulic fluids are a main example of this trend because of the transition from monograde to multigrade offerings to enhance efficiency and reduce fuel consumption. Package suppliers will need to adjust their products to meet increasing performance demands such as improved lubrication, wear protection and corrosion resistance.”

Langston believes the use of multifunctional additives and additive packages is already widespread. He says, “While some formulations and applications may require careful development on an individual additive basis, many formulators will benefit from robust additive package solutions that expedite development timelines an simplify manufacturing processes.”

Willett foresees that several market factors will prompt formulators to turn to multifunctional additives. He says, “Demands of lower ash engine oils, environmental, health and safety standards and the growth of more environmentally friendly lubricants will prompt formulators to use multifunctional additives because of the overall reduction in the level of active chemistry in formulations. One multifunctional additive may reduce the overall weight percent of components used in a formulation and therefore reduce the overall number of chemistries which must be regulated continuously.”

As part of this process, Willett believes that additive suppliers will turn to more specialized multifunctional chemistries as a core of new products will also allow brands to differentiate themselves better in the highly competitive lubricant market. 

Driver says, “Multifunctional additives are an important part of a formulator’s toolbox. Their use always depends on a careful balance of cost, performance and the benefits and detriments of a specific additive relative to the performance requirements of the application. The development of multifunctional components and packages in lubricants is an exciting journey driven by continuous scientific advancements. These new developments are essential for creating effective solutions that improve performance and efficiency for future generations. Our growing understanding of lubricant additives allows us to design products that perform multiple tasks and leads to improved performance to meet ever increasing performance and regulatory requirements.”

Alvarez indicates that multifunctional additives and additive packages will continue to be utilized in all applications where they are currently employed. He says, “Wherever there are moving parts that require lubrication, cooling and protection, multifunctional additives and additive packages will provide the necessary protection.”

Although multifunctional additives are already widely used, the potential for raising their consumption is still very high, according to Grabarz. He concludes, “Research is being conducted on the development or modernization of the compositions in multifunctional additives for use in specific geographical regions.” Areas of interest include the development of multifunctional additives and additive packages using higher levels of biobased and/or renewable raw materials. This includes testing of performance to verify improved compatibility with a wide range of additive chemistries in highly refined or biobased fluids. 

Formulators will need to continue to work with multifunctional additives and additive packages in most of the main lubricant applications. They offer significant benefits that cannot be ignored by formulators. Selection of a particular additive will be dictated by the specific application, cost performance and regulatory trends that may restrict the use of specific components.
REFERENCES
1. Spikes, H.A. (2004), “The history and mechanism of ZDDP,” Tribology Letters, 17 (3), pp. 469-489.
2. Rudnick, L., Editor (2022), Lubricant Additives Chemistry and Application, 3rd Edition, CRC Press.
3. Jha, A. and Wall, D. (2025), “Insights into synergistic workings of additives improving engine cleanliness performance of lubricant oils,” Presented at the STLE Annual Meeting in Atlanta, Ga., in May 2025. 
4. Fish, G., McCune, D.K. and Dura, R.D. (2023), “Formualting challenges in an increasingly regulated world,” Presented at the ELGI Annual Meeting in Amsterdam, The Netherlands, in May 2023.