In recent decades, advances in additive technology have played a pivotal role in the development of modern industry, underpinning the performance of high-end lubricants and greases. Today, this field has reached a remarkable level of sophistication, with current trends increasingly oriented toward specialized applications and the pressing needs of environmental sustainability and energy efficiency. We are grateful to the editorial board of Lubricants for the invitation to organize this Special Issue, which has provided us with a valuable opportunity to highlight these developments. It is with this focus that we present “Novel Lubricant Additives in 2025.”
This collection brings together cutting-edge research that collectively addresses the multi-faceted challenges of modern lubrication. The seven contributions progress logically from molecular design and performance understanding to novel material exploration and sustainable formulation, ultimately converging on the shared goals of efficiency, durability, and ecological responsibility.
Opening the Issue, Shi et al. from Sinopec Lubricant Research Institute, a leading research institution in China, provide a fundamental study on the structure–performance relationship of PMA viscosity index improvers tailored for new energy vehicle transmission fluids. Their work establishes a crucial molecular-level foundation, demonstrating how tailored architectures govern key fluid properties under demanding electromechanical conditions.
Building on the theme of performance under specific constraints, Polajnar et al. delve into the friction-reduction mechanism of a perfluorinated additive under full-film elastohydrodynamic lubrication. Their systematic parameter study complements the previous work by highlighting how additive functionality is critically dependent on base oil polarity, concentration, and contact pressure—a vital lesson for formulation engineering.
Shifting focus toward sustainable alternatives, the next two papers explore eco-friendly systems. First, Huang et al. demonstrate the efficacy of boric acid in enhancing the extreme-pressure performance of glycerol ethoxylate aqueous lubricants, offering a promising pathway to replace traditional oil-based systems. Advancing this pursuit of green lubricants further, Li et al. present a breakthrough in marine hydraulic fluids. By incorporating phytic acid, they achieve an ultra-low friction coefficient, superior heat suppression, and low biotoxicity, showcasing a high-performance, environmentally considerate solution for sensitive offshore ecosystems.
Parallel to the search for new chemistries is the exploration of novel functional materials. Cheng et al. investigate the tribological potential of Y2BaCuO5, a high-temperature superconductor precursor, as an oil additive. Their findings reveal significant load-dependent friction reduction, introducing an intriguing class of multifunctional materials and highlighting the ongoing quest for unconventional additive platforms.
Returning to the optimization of conventional systems, Zhang et al. introduce a novel class of organic friction modifiers based on melamine long-chain alcohol esters. Their sulfur- and phosphorus-free design exhibits exceptional thermal stability and outstanding anti-wear performance up to 200 °C, addressing the critical need for durable, high-temperature additives in advanced engines—a direct response to the efficiency demands highlighted in the first paper.
Finally, Smigins et al. provide a crucial perspective on the complex reality of commercial additive formulation. Their evaluation of a multifunctional additive package in engine oil underscores that performance is not merely additive but systemic, emphasizing the importance of rigorous, condition-specific validation—a concluding note that reinforces the integrated and application-driven nature of modern lubricant development.
Collectively, these studies delineate a coherent progression—from elucidating molecular interactions and pioneering novel materials to engineering solutions for targeted applications and assessing their efficacy in complex systems. This body of work illustrates a discipline that is not only consolidating its foundational understanding but also expanding its horizons toward sustainability and greater specialization.
We extend our sincere gratitude to all the authors for their valuable contributions and to the reviewers for their rigorous and constructive feedback. At the same time, I would like to extend my sincere thanks to Dr. Hongmei Yang for her dedicated efforts in coordinating contributions. We also thank the editorial team of Lubricants for their support throughout the preparation of this Special Issue. It is our hope that this collection will inspire further research and collaboration in the quest for smarter, cleaner, and more efficient lubrication technologies.
Conflicts of Interest
The author declares no conflicts of interest.
List of Contributions
- Yin, J.; Shi, X.; Lei, L.; Cao, J.; Zhao, Q.; Zhao, H. Structure–Performance Relationship Study of PMA Viscosity Index Improver in New Energy Vehicle Transmission Fluid. Lubricants 2026, 14, 4. https://doi.org/10.3390/lubricants14010004.
- Huang, S.; Wang, Z.; Hao, Z. Boric Acid as an Effective Lubricant Additive in Glycerol Ethoxylate Aqueous Solution. Lubricants 2025, 13, 414. https://doi.org/10.3390/lubricants13090414.
- Cheng, S.; He, L.; Xu, J. Exploring the Tribological Potential of Y2BaCuO5 Precursor Powders as a Novel Lubricant Additive. Lubricants 2025, 13, 315. https://doi.org/10.3390/lubricants13070315.
- Smigins, R.; Žunda, A.; Andriušis, A.; Acar, Ç.; Tučkutė, S. The Influence of Atomic Metal Conditioner Additive with Surface Revitalizer on the Lubricating Properties of Engine Oil. Lubricants 2025, 13, 284. https://doi.org/10.3390/lubricants13070284.
- Polajnar, M.; Požar, T.; Kalin, M. Perfluorotetradecanoic Acid as an Additive for Friction Reduction in Full-Film EHD Contacts: The Role of Functional Group, Base Oil Polarity, Additive Concentration and Contact Pressure. Lubricants 2025, 13, 263. https://doi.org/10.3390/lubricants13060263.
- Zhang, J.; Hu, W.; Li, J. Enhanced Tribological Performance of Melamine Long-Chain Alcohol Esters in High-Temperature Boundary Lubrication. Lubricants 2025, 13, 114. https://doi.org/10.3390/lubricants13030114.
- Li, W.; Chen, H.; Chen, L.; Ge, S.; Cai, Q.; Gong, G.; Yu, J.; Nishimura, K.; Jiang, N.; Cai, T. Low Brine Shrimp Bio-Toxicity Marine Lubricating Hydraulic Fluid with Ultra-Low Friction Coefficient and Enhanced Frictional Heat Suppression. Lubricants 2025, 13, 103. https://doi.org/10.3390/lubricants13030103.
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