Browse Topic: Lubricants

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Influence of Copper oxide and Graphite additives on the lubrication performance of the engine oil2026-28-0017To be published on 02/01/2026
The parts of engine move at high speeds under heavy pressure. This leads to high temperatures and wear. To reduce the rate of wear, lubricants are used. But the lubricants are pollutants and increasing their useful life will result in the reduction of pollution. Additives may help in increasing the useful life of a lubricant. In the present study, the effect of the addition of cupric oxide and graphite nanoparticles to the engine oil on its performance of lubrication using pin on disc tribometer. AA2014 – 5 wt.% TiC composite material sliding against steel surface with lubricant was used to quantify the performance of additives. The base lubricant used in this study was 5W30 grade engine oil. Two types of lubricants, engine oil with 2 wt.% copper oxide (CuO) and engine oil with 2 wt.% Graphite (Gr) were tested and compared with the performance of the base oil in similar conditions. Adding Gr particles to the oil reduced the wear rate of sample by nearly 40% while CuO particles reduced
Ch, Sri Chaitanya, Mutyala, Venkata Ramarao, PONNAGANTI, Gopinadh Chowdary, Rajamalla PhD, Narasimha Rao, Bachugudem, Arun Kumar, Abdul Azeez, Mohammed, Kumar, Mohan
Modelling and Analysis of Hypoid Gear Churning Loss in Rear Drive Axle: The Role of Oil Viscosity and Empirical Parameters2026-26-0508To be published on 01/16/2026
This definitive study investigates the variation of churning losses occurring with hypoid ring and pinion gear sets and puts primary importance to factors that determine energy dissipation in these mechanisms. A detailed investigation shows that viscosity is critical, particularly due to large temperature-dependent variations. Besides this, the study focuses on particular attention to experimental parameters derived from measured data to model churning losses. Churning Loss itself originates in the interaction between the rotation of the gears and the lubricating oil - a source of significant inefficiency within the overall drivetrain. A robust, comprehensive model has been formulated to take this into account. It does not only account for variable oil viscosity with temperature but integrates key empirical parameters that reflect observed behaviours in gear systems. The study adopts a multidimensional approach by considering the influence of various other factors. It investigates how
Khan, Aliya Javid, Praveen, Abhinav, Kanagaraj, Pothiraj, Jain, Saurabh Kumar, AP, Baaheedharan
"Exploring the Effects of Oil Cooler Deletion on Tractor Engine Operation"2026-26-0547To be published on 01/16/2026
Cost reduction remains a significant challenge for engine manufacturers, particularly for off-highway application vehicles. An optimal engine lubrication system, encompassing engine oil and an oil cooler, is critical for thermal management and minimizing frictional losses. This system ensures adequate lubrication and cooling of engine components, thereby maintaining optimal performance. This study investigates the implications of oil cooler removal in a 45HP inline engine tractor. Various validation trials were conducted, including high ambient temperature tests under worst-case conditions, high coolant temperature scenarios, and a rigorous tractor killer test. In the latter, the tractor underwent 100 hours of operation on a PTO bench at maximum engine RPMs. Despite an observable increase in lubricant oil temperature during these tests, the tractor did not exhibit any component seizure or failure. The findings aim to determine whether the inclusion of an oil cooler is essential for the
Gupta, Deepak, Kumar, Pankaj, Singh, Manjinder, Singh, Gagandeep, Kumar, Munish, SINGH, HARPREET, Singh, Maninder
Optimization of Negative Crankcase Pressure Mechanism to Minimize Oil Pumping into Combustion chamber and Ensure Particulate Number Compliance in Euro VI Emission for Naturally Aspirated Gas Engine.2026-26-0223To be published on 01/16/2026
Emissions regulations, such as Euro VI, drives the Automotive industry to innovate continuously in Engine development. One significant challenge is the engine oil pumping from the crankcase into the combustion chamber, where it participates in combustion, which contributes to increased Particulate Numbers and fails to meet Euro VI emission compliance. This issue is most noticeable during engine idling and motoring conditions. During this time, a higher negative pressure difference develops between the intake manifold, which is acting above the combustion chamber and the engine crankcase. This pressure difference drives oil-laden blow-by aerosols past piston rings during the intake stroke and through the valve stem seals, allowing oil into the combustion chamber. The impact of the pressure difference between the intake manifold and crankcase was studied by varying the crankcase pressure through crankcase ventilation system. The results confirm that oil entry into the combustion chamber
R, MAHESH BHARATHI, Bondfale, Shubham, Jeyaprakasan, Dharoon Gautham
EV Transmission efficiency estimation using Simulation X2026-26-0453To be published on 01/16/2026
Electric vehicle (EV) transmission efficiency is crucial for optimizing energy use and enhancing performance. It minimizes power losses during energy transfer from the motor to the wheels, directly impacting the vehicle's range and battery life. High efficiency ensures smoother acceleration and better driving dynamics, improving the overall user experience. Unlike internal combustion engine (ICE) transmissions, EV transmissions often employ simpler, single-speed systems, reducing complexity and energy loss. Efficient transmissions help reduce energy usage, lower costs, and minimize environmental impact. As a result, transmission efficiency plays a vital role in ensuring the sustainability and reliability of EV designs. This paper proposes a simulation model based methodology to estimate EV transmission efficiency based on modelica models developed on simulation X. A single speed EV model is developed which contains whole transmission layout discretized into simple components which
Sutar, Suresh, Thambala, Prashanth, Patel, Hiral
Exploring advanced additive chemistry for achieving fuel economy in passenger car motor oils2026-26-0529To be published on 01/16/2026
Original Equipment Manufacturers (OEM’s) are focusing towards fuel economy of passenger cars to meet the next generation emission norms. Few techniques such as downsizing of engines, raising lubricant temperature, reducing combustion time and regulating the start-stop system of engines are various efforts being considered by Automobile OEMs to attain fuel efficiency along with next generation emission norms. On the other hand, lubricants used for such engines are also to be modified accordingly to meet more fuel efficiency. Lowering viscosity along with addition of friction modifiers for normalizing frictional losses is widely practiced as the most economical techniques. To achieve this lubricant formulator and additive manufacturers have moved towards modern base oils and advanced additive technologies. This study is done to understand key parameters which reduce friction and increase fuel economy using same viscosity grade oils. In the current study, we have formulated different low
Vabbina, Dr Shiv Kumar, Katta, Dr Lakshmi, Joshi, Dr Ratnadeep, Chaudhary, Dr Rameshwar, Seth, Dr Sarita, Bhardwaj, Dr Anil, Arora, Dr Ajay Kumar
Advanced Sensor less Machine Learning Technique for Early Detection of Engine Oil Degradation2026-26-0656To be published on 01/16/2026
Maximizing vehicle uptime and reducing maintenance costs are critical objectives in modern automotive systems, making efficient resource utilization a top priority. One key factor is engine oil degradation, which directly affects engine performance, longevity, and overall vehicle efficiency. Current Conventional oil monitoring approaches are real time based on dedicated sensors—can be inefficient, costly, or poorly adapted to varying usage conditions. While earlier studies have explored sensor-based or chemical analysis methods for oil health monitoring, these solutions often lack scalability and cost-effectiveness for widespread adoption. This paper introduces a Machine Learning-based Engine Oil Degradation Detection System that operates non-intrusively using existing vehicle CAN signals, requiring no additional sensors. Key engine parameters such as RPM, Torque, Gear Position, Engine Power, Coolant Temperature, and Odometer readings are trained with tri-bological properties
Dusane, Mangesh, Tade, Vilas, Iqbal, Shoaib
Engine oil fluctuation study in HLA gallery and impact of VVT cam phasing on oil fluctuation.2026-26-0559To be published on 01/16/2026
Oil pressure, the most fundamental to engine's performance and longevity, is critical as it ensures that the engine components are properly lubricated, cooled, and protected against wear and contamination, ultimately contributing to reliable engine performance. Due to several factors of engine, such as speed and load, there are fluctuations in oil pressure, which can be controllable and sometimes unpredictable. Controlled oil pressure fluctuations are essential for engine efficiency and adaptability, such as adaptive lubrication, temperature compensation, and hydraulic component functioning like variable valve timing, VVT, and hydraulic lash adjuster, HLA. But excessive or irregular fluctuations can indicate serious issues like excessive or sudden drops, unstable engine performance, valve train noise, improper lifter operation, VVT malfunctions, overheating, and increased wear. In this paper, HLA gallery pressure fluctuations are studied, and its impact was assessed on valve train
Kumar, Ashok, Choubisa, Manas, Kumar, Ravi, pathak, Mehul
Experimental approach to investigate VVT malfunction in SI gasoline engine.2026-26-0558To be published on 01/16/2026
Variable Valve Timing (VVT) is an advanced technology implemented in internal combustion engines to optimize the opening and closing timing of the intake and exhaust valves. Its primary objective is to improve engine performance, fuel efficiency, and reduce emissions by dynamically adjusting the valve timing based on the engine's operating conditions i.e. engine speed and load conditions. However, the VVT system may experience various operational issues caused due to low engine oil levels, contaminated engine oil, solenoid malfunctions, and camshaft phaser issues, which can adversely affect engine performance, fuel efficiency, and emissions. This paper provides an in-depth analysis of VVT malfunctions, specifically attributed to the resonance effect of VVT components at various engine RPMs & oil temperature. The study also explains the phenomenon causing VVT sluggishness during advance phase due to resonance between oil pulsation & VVT components. Other factors contributing to VVT
Jha, Ankur, Sau, Sanjoy, Kumar, Bharat, Sandeep, Sandeep
Experimental Analysis of Hydrocarbon Injection Strategies and In-Cylinder Injection Impact on Oil Properties in Diesel Engines2025-28-023811/06/2025
The engine has played a pivotal role in controlling regulated pollutants at the in-cylinder combustion level through strategies such as Direct Injection, Common Rail Systems, and Exhaust Gas Recirculation up to Bharat (CEV/Trem) Stage-III. With the advent of more stringent emission norms, specifically Bharat (CEV/Trem) Stage-IV and V, the importance of Exhaust After-Treatment Systems (EATS) in managing emissions outside the engine has significantly increased. The inclusion of Particulate Number (PN) limits in Bharat (CEV/Trem) Stage-V necessitates the use of Diesel Particulate Filters (DPF), which trap soot particles that must be periodically removed through a process known as regeneration. Regeneration requires elevated exhaust temperatures, typically achieved via exothermic reactions in the Diesel Oxidation Catalyst (DOC), facilitated by diesel fuel addition through external injection or in-cylinder injection strategies. This study investigates both external and in-cylinder injection
Bandaru, Balaji, M, Balasubramanian, V, Shunmuga, G, Senthil Kumar, Mahesh, P
Ca Additive and In-Cylinder Condition on Promotion of Abnormal Combustion in Supercharged SI Engine2025-32-000411/03/2025
Recently, global warming is becoming seriously. In the field of internal combustion engine, the thermal efficiency has to improve in the practical use. One of the current trends with spark ignition engine (SI engine) is “downsizing” which is equipped supercharger with the downsized displacement. The downsizing engine is popular in the field of the SI engine. However, one of the problems is the abnormal combustion so called Low Speed Pre-Ignition (LSPI) [1]. The LSPI occurs the engine operation which is low speed and high load condition. It has to be avoided, because the SI engine is broken and the improvement of thermal efficiency is obstructed. A lot of researchers have been reported about the mechanism of LSPI [2, 3]. One of the sources of LSPI would be the lubricating oil droplets in cylinder. One of the methods to avoid LSPI, it has been adjusted the ingredients of oil additive in lubricating oil. The state of the art of lubricating oil standard has been established anti-LSPI
kitano, Kaito, Tanaka, Junya
Torque Transfer Response Enhancement on the DCT with Estimated Hydraulic Pressure in the Clutch Piston Chamber2025-32-008311/03/2025
The torque transfer response to rider throttle operation contributes to vehicle control in motorcycles equipped with a DCT (Dual Clutch Transmission). The clutch response is a key parameter to enhance torque transfer response. We have developed three new ECU (Electric Control Unit) control methods to enhance the clutch response on the DCT. The DCT clutch transfers torque by controlling the contact force between the clutch discs and the clutch plates. It is desirable to measure the hydraulic pressure value directly from the clutch piston chamber to control the contact force. However, since the clutch piston is a rotating body, it is impractical to place a hydraulic pressure sensor on it. Therefore, the hydraulic pressure sensor is placed along the clutch control oil line at the existing DCT system. Consequently, when oil flows in the oil line, pressure loss in the oil line causes a deviation between the hydraulic pressure sensor value and the clutch piston chamber pressure value, which
Takahashi, Kosaku
A Novel Approach to Enhance Compressor Life in Passenger Vehicle MAC Systems2025-28-040910/30/2025
Compressor durability is a critical factor for ensuring the long-term reliability of Mobile Air Conditioning (MAC) systems in passenger vehicles. This study presents a software based strategy for enhancing compressor life using Smart Fully Automatic Temperature Control (FATC), requiring no additional hardware. The proposed approach leverages existing inputs from the FATC and Engine Management System (EMS) to intelligently manage compressor operation, with a focus on addressing challenges related to prolonged non-usage. In extended inactivity scenarios such as during cold weather, vehicle exportation, storage, or breakdowns, lubrication oil tends to settle in the compressor sump, leaving internal parts dry. Sudden reactivation at high engine speeds under such conditions can cause increased friction, wear and even compressor seizure. To mitigate this, an intelligent reactivation protocol has been developed and integrated into the Climate Control Module (CCM). This protocol continuously
Deshmukh, Ganesh, Chotaliya, Bhavy, Kulkarni, Shridhar, KHAIRE, DATTATRAY, Jaybhay, Sambhaji, Joshi, Gaurav, Shah, Geet
Rubber: Fluorosilicone (FVMQ) High Temperature Fuel and Oil Resistant For Seals In Fuel Systems and Specific Engine Oil SystemsAMS7273D (Current)10/24/2025
This specification covers a fluorosilicone (FVMQ) rubber in the form of molded rings.
AMS CE Elastomers Committee
Literature on Gas Turbine Engine Lubricant Composition and Degradation Relevant to Cabin Air QualityAIR5784A (Current)10/15/2025
The previous revision of AIR5784 summarizes some of the available literature on cabin air study, engine oil composition, decomposition, and toxicity testing. This revision of AIR5784 includes literature and information on stakeholder involvement, selected air sampling studies, oil composition, and oil degradation, published from 2000 to 2023. The entire contents of the reviewed literature are not necessarily endorsed by either SAE or the members of the study group who produced it. This is not a comprehensive review but is intended to enable E-34 and other technical organizations to participate in informed discussions on the topic. Also, the review is intended to indicate where additional work may be necessary to properly gauge the potential role that turbine lubricants (and OPs) play in cabin air quality. The toxicology of oil fumes and their individual constituents is beyond the scope of this document and outside the remit of this committee.
E-34 Propulsion Lubricants Committee
Impact of Oil Composition on Pre-Ignition in a Hydrogen Engine04-18-03-001810/10/2025
Pre-ignition (PI) is a common issue in internal combustion engines (ICE) with spark ignition. While the various causes have been identified with conventional fuels (such as gasoline or gasoline blends), the causes with hydrogen in ICE are not yet fully understood. This article presents the results of investigations into the influence of seven different lubricating oils on PI in a single-cylinder hydrogen research engine. The variation of two different parameters at two engine speeds were investigated: load and air/fuel mixture. For both variations, the tests start at the same conditions and run until the operating limit of the engine is reached (peak firing pressure, or maximum intake manifold pressure). The PI and knocking PI are investigated, while classifying them according to the peak cylinder pressure. It has been observed that enleanment above λ = 2.4 can lead to higher PI rates, while simultaneously reducing the knocking PI. During the load sweep at 2000 1/min, the highest
Pehlivanlar, Benjamin, Torkler, Michael, Fischer, Marcus, Göbel, Christoph, Pischinger, Stefan, Maulbetsch, Theo, Nübling, Fritz, Neumann, Stephan
Influence of Microtexture’s Parameters on Improving the Lubrication Performance of Crankpin Bearings in Engine04-19-02-000610/09/2025
The force of the solid contact (Fsc ) between the bearing surface and the shaft surface and the friction force (Ffri ) generated in the crankpin bearing have a great influence on the lubrication performance of the crankpin bearing in the engine. Therefore, the micro-circular texture (MCT) has been proposed and designed on the bearing surface of the crankpin bearing for ameliorating its lubrication performance. To evaluate the effectiveness of MCT in detail, based on the lubricating model of the crankpin bearing under the impaction of external load F 0, the influence of the density, depth (hMCT ), and radius (rMCT ) of MCT on the characteristics of the pressure (p) of oil film, thickness of oil film (h), force of solid contacts, and force of the friction in the crankpin bearing are also investigated, respectively. An algorithmic program written in a MATLAB environment is then applied to simulate the lubrication equations of the crankpin bearing and MCT. Some outstanding results of the
Jiao, Renqiang, Nguyen, Vanliem
Grease innovation adapts to meet new demands of heavy equipment25TOFHP10_0510/01/2025
In the commercial and off-highway sectors, equipment reliability isn't just a maintenance target but a business imperative. Whether it's a long-haul truck on the interstate or a dozer working through dust and rock, these machines operate in some of the most demanding environments on Earth. And while engine design and fuel choice often dominate conversations about performance, the role of grease is just as critical, particularly as equipment is pushed harder and longer under more variable conditions. Over the last decade, heavy-duty grease development has undergone a quiet evolution. Performance expectations have risen sharply. So have the environmental and regulatory considerations that influence formulation decisions.
Kumar, Anoop
Visualization Analysis of Hydrogen Combustion Triggered by Non-Controlled Hotspots Using a Rapid Compression Expansion Machine2025-24-004709/07/2025
Research on hydrogen-fueled internal combustion engines has gained growing attention as a carbon-neutral solution to reducing emissions in the transport sector. However, challenges remain, with the risk of abnormal combustion being one of the major criticalities. This paper aims to clarify the ignition process of a hydrogen-air mixture caused by lubricant oil droplets and soot deposition. To achieve this, high-speed imaging methods were applied with a Rapid Compression Expansion Machine under engine-like conditions. Direct imaging and OH* chemiluminescence were captured simultaneously on the engine head to visualize the ignition point and flame propagation. Different operating conditions were tested to evaluate the influence of lambda, intake pressure, and soot quantity on ignition occurrence. For each test bench configuration, ten successive tests were conducted to assess the probability of ignition. The presence of soot was ensured through a preliminary run with diesel injection. The
Tempesti, Claretta, Yukitani, Takumi, Horibe, Naoto, Romani, Luca, Ferrara, Giovanni, Kawanabe, Hiroshi
Experimental Study of the Lubricating Oil Impact on the Unsteady Performance of an Automotive Turbocharger2025-24-007809/07/2025
Turbocharging technique is a key technology for the development of hydrogen engines, allowing high lambda values to reach low NOx emissions. In ultra-lean mixture conditions, the thermal management of the lubricating oil and its cold condition becomes a crucial aspect that cannot be neglected. Accordingly, the impact of different lubricating oils and different lubricant thermal conditions is highlighted referring to the performance of a turbocharging system for automotive application. To this aim, an experimental campaign is conducted at the test bench for components of propulsion systems of the University of Genoa. Tests are performed on a turbocharger equipped with a variable geometry turbine under both steady and unsteady flow conditions, considering different positions of the turbine regulating device. A 4-cylinder engine head was coupled to the turbocharger in order to reproduce the pulsating flow related to the opening and closing of the engine valves. The influence of the
Marelli, Silvia, Usai, Vittorio, Cordalonga, Carla
A Study on Sensitive Spots in Hydrogen Engines2025-24-005909/07/2025
Premature self-ignitions in hydrogen internal combustion engines have been associated with the presence of hot spots. However, local increases in charge reactivity may be triggered not only by elevated temperatures but also by composition inhomogeneities. Such non-uniformities, in addition to imperfect mixing (e.g., in the case of direct hydrogen injection), may result from external contamination by more reactive components, such as lubricant oil. The present study aims to shed light on the mechanism through which lubricant oil contamination leads to the formation of sensitive spots, by analysing the behaviour of an isolated droplet suspended in a hydrogen/air environment. The “HyLube” chemical kinetic mechanism was employed to reproduce the chemical behaviour of lubricant oil, as it was specifically developed for this purpose. A one-dimensional numerical model was used to simulate the heating, vaporization, and combustion of the droplet. Zero-dimensional simulations were also
Distaso, Elia, Baloch, Daniyal Altaf, Amirante, Riccardo, Tamburrano, Paolo
Numerical Study of Mixing, Combustion and NOx Emissions in a DI High Performance Hydrogen Engine Operated at Stoichiometry2025-24-001009/07/2025
The roadmap towards carbon neutrality by 2050 makes necessary drastic reduction of road vehicle tailpipe carbon emissions. One viable approach to reach the abatement of carbon monoxide and dioxide is to fuel internal combustion engines (ICEs) with hydrogen. The burning of a hydrogen-air mixture inside the combustion chamber reduces to minimal amount the production of carbon emissions and particulate matter that are only produced by the presence of lubricant oil. However, the high temperatures reached by the end-gases promote the formation of nitrogen oxides. In high-performance ICEs, the pursuit for high-specific power by means of the adoption of stoichiometric mixtures is hindered by the need to reduce NOx - as this pollutant drastically drops when moving towards ultra-lean mixtures. The paper aims to present a CFD-3D framework to simulate the full engine-cycle of a high-performance Spark-Ignited (SI) Direct-Injection (DI) ICE fuelled at stoichiometric conditions. The methodology is
Baudone, Antonio Denny, Marini, Alessandro, Sfriso, Stefano, Falcinelli, Francesco, Mortellaro, Fabio, Tonelli, Roberto, Breda, Sebastiano
Silicone Compound, NATO Code Number S-736AMS8660A (Current)08/22/2025
This specification covers one type of a non-melting, heat-stable silicone compound, for use in high tension electrical connections, ignition systems, and electronics equipment, for application to unpainted mating threaded or non-threaded surfaces, and as a lubricant for components fabricated from elastomers. This compound is effective in the temperature range from -54 °C (-65 °F) to +204 °C (400 °F) for extended periods. This compound is identified by NATO symbol S-736 (see 6.5).
AMS M Aerospace Greases Committee
O-Ring Molded from AMS7274 MaterialAS3570A (Current)07/17/2025
This standard establishes the dimensional and visual quality requirements, lot requirements, and packaging and labeling requirements for O-rings molded from AMS7274 rubber. It shall be used for procurement purposes.
A-6C2 Seals Committee
Specification for Aero and Aero-Derived Gas Turbine Engine LubricantsAS5780E (Current)07/17/2025
This specification defines basic physical, chemical, and performance limits for 5 cSt grades of gas turbine engine lubricating oils used in aero and aero-derived marine and industrial applications, along with standard test methods and requirements for laboratories performing them. It also defines the quality control requirements to assure batch conformance and materials traceability and the procedures to manage and communicate changes in oil formulation and brand. This specification invokes the Performance Review Institute (PRI) product qualification process. Requests for submittal information may be made to PRI at the address in 2.1.3, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by PRI. Additional tests and evaluations may be required by individual OEMs before an oil is approved for use in their equipment. Approval and/or certification for use of a specific gas turbine engine oil in aero and aero
E-34 Propulsion Lubricants Committee
Method for Externally Controlled Availability of Lubricating Oil in Internal Combustion Engines2025-01-030207/02/2025
Reduced raw emissions from internal combustion engines (ICE) are a key requirement to reach future green-house-gas and pollutive emissions regulations. In parallel, to satisfy the need for increased engine efficiencies, the friction losses of ICEs gains attention. Measures to reduce parasitic drag inside the piston assembly such as reduced piston-ring pretension or thinner grade engine oils may increase oil ingress into the combustion chamber. The oil ingress is known to imply increased particle emissions directly counteracting the raw emission reduction target of engine development. To resolve this target conflict, the transport mechanisms of oil into the combustion chamber are the topic of current research. Specially developed research engines featuring a vertical optical window come with big potential to visualize the phenomena of the oil behavior inside the piston assembly group. Such ‘glass-liner’ engines play a pivotal role in identification and quantification of local and global
Stark, Michael, Fellner, Felix, Härtl, Martin, Jaensch, Malte
Grease: Wide Temperature Range Lithium or Lithium Complex Thickened for Aircraft Wheel BearingsAMS3058B (Current)06/30/2025
This specification covers grease for use on aircraft wheel bearings. It also defines the quality control requirements to assure batch conformance and materials traceability and the procedures to manage and communicate changes in the grease formulation and brand. This specification invokes the Performance Review Institute (PRI) product qualification process. Requests for submittal information may be made to the PRI at the address in 2.2, referencing this specification. Products qualified to this specification are listed on a qualified products list (QPL) managed by the PRI. Additional tests and evaluations may be required by individual equipment builders before a grease is approved for use in their equipment. Approval and/or certification for use of a specific grease in aero and aero-derived marine and industrial applications is the responsibility of the individual equipment builder and/or governmental authorities and is not implied by compliance with or qualification to this
AMS M Aerospace Greases Committee
Grease, Aircraft, General Purpose, Low Temperature Range, Lithium ThickenedAMS3052B (Current)06/30/2025
This specification covers grease for use within an aircraft. It also defines the quality control requirements to assure batch conformance and materials traceability and the procedures to manage and communicate changes in the grease formulation and brand. This specification invokes the Performance Review Institute (PRI) product qualification process. Requests for submittal information may be made to the PRI at the address in 2.2, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by the PRI. Additional tests and evaluations may be required by individual equipment builders before a grease is approved for use in their equipment. Approval and/or certification for use of a specific grease in aero and aero-derived marine and industrial applications is the responsibility of the individual equipment builder and/or governmental authorities and is not implied by compliance with or qualification to this specification.
AMS M Aerospace Greases Committee
Heavy-Duty Vehicle Lubricating GreasesJ2695_202506 (Current)06/30/2025
This SAE Recommended Practice was developed by SAE and the section “Standard Classification and Specification for Service Greases” cooperatively with ASTM and NLGI. It is intended to assist those concerned with the design of heavy-duty vehicle components and with the selection and marketing of greases for the lubrication of certain components on heavy-duty vehicles like trucks and buses. The information contained herein will be helpful in understanding the terms related to properties, designations, and service applications of heavy-duty vehicle greases.
Fuels and Lubricants TC 3 Driveline and Chassis Lubrication
Investigating Lubricants Base Oils Reactivity in Ammonia Engines via Accelerated Aging2025-01-024006/16/2025
As a carbon-free molecule, ammonia is more and more considered as a relevant fuel for long distance and off-road applications. However, this gas has different combustion characteristics compared to conventional fuels, challenging the suitability of lubricants to such engines. In this work, the evolution of lubricants under conditions mimicking ammonia combustion was assessed. Mineral and polyester lubricant base oils were exposed to oxygen, nitrogen oxides, and ammonia in a pressurized reactor under stirring. Oil aliquots were sampled at regular intervals, and characterized using Fourier Transform Infrared Spectroscopy (FTIR), viscosity and total oxygen and nitrogen contents measurements. Exposure to air containing nitrogen oxides resulted in quicker accumulation of oxidation products compared to neat air, for both the mineral and complex polyester base oil. Besides, exposure to gaseous ammonia in air resulted in a slower oxidation rate for both oils, compared to neat air. A global
Doncoeur, Carole, Giarracca, Lucia, Cologon, Perrine, Rousselle, Christine
CFD Study of Lubrication Pump Starvation Due to Oil Pan Sloshing2025-01-021306/16/2025
Dynamic vehicle operation, such as acceleration, deceleration, and tilting, can cause severe oil sloshing in the engine oil pan. This can lead to oil starvation at the pickup tube, compromising lubrication pump performance, and potentially damaging engine components. This study presents a Computational Fluid Dynamics (CFD) multiphase model of an engine oil pan and a system of lubrication pumps, simulated using Simerics-MP+®. A series of numerical simulations are conducted at a given pump speed and extreme oil pan tilt angles or accelerations relevant to a high performance vehicle. Time-dependent oil distributions are visualized, and real-time oil flow rates are monitored at the pickup tubes to assess the impact of oil dynamics and pan position on pick-up tube starvation. This CFD model provides valuable insights into oil pan and pump behavior under extreme vehicle operation conditions, aiding in the design and optimization of lubrication systems to mitigate the risk of oil starvation
Nan, Zhang, Shiyi, Pan, Jing, Liu, Mingliang, Liu, Wei, Wang
Modern Low Friction Coating Technology for Automotive Tribology2025-01-024706/16/2025
The aim of this work is to present the overviewing results of the low friction coating technology for modern automotive application with the themes, e.g. electric vehicle (EV), R&D trends and bioethanol fuel application. According to Forbes, China, armed with EV, could have several companies among the top 10 global brands by sales in 2030. EV’s friction is more severe than traditional powertrain friction. For the protection of EV’s wear and friction, the coatings, diamond like carbon (DLC) and CrCuN, are compared in the literature. Global coating companies developed with the keywords: hybrid process, low-temperature coating process for polymer material. Last coating conferences showed R&D trends: coating for polymer materials, tetrahedral amorphous carbon (taC) coating, low-temperature coating process and multi-elements containing coatings. In Korea, research institutions, universities and Hyundai Motor Group have a long-term project for the development of ultralow friction coatings of
Cha, Sung Chul, Moon, Kyoung Il, Kim, Jongkuk, Park, Chang Ho, Kim, Dong Sik
Experimental Analysis of Performance and Durability Using Ethanol 27% Fuel Blend in a Turbocharged Gasoline Direct Injection Engine2025-01-024506/16/2025
India aims to achieve 20% ethanol blending (E20) in petrol by 2025 under its National Biofuels Policy to reduce carbon emissions, enhance energy security, and support the agricultural economy. Building on this, E27 (27% ethanol in gasoline) is being evaluated as an advanced mid-level blend to further lower greenhouse gas emissions and reduce reliance on fossil fuels. This study investigates the performance, emissions, and combustion characteristics of a turbocharged gasoline direct injection (TGDI) engine using E27 fuel over 20,000 km in real-world driving conditions, as part of a broader research program accumulating over 100,000 km across multiple vehicle categories. Key findings indicate that E27 achieves an optimal balance of emissions reduction and performance, with NOx and THC emissions decreasing by 12% and 5%, respectively, compared to E10, while CO and CO₂ levels remained stable, reflecting ethanol’s oxygenation effect and lower carbon intensity. Power output and acceleration
D R, Vigneshwar, Bhakthavachalu, Vijayabaskar, Muralidharan, M.
Maintaining protection for next-gen HD engine lubricants25TOFHP06_0906/01/2025
The American Petroleum Institute's (API) Proposed Category 12 (PC-12) is currently under development. A target first license date has been set for January 2027, and industry stakeholders are currently at work on PC-12's testing requirements, limits and other criteria that will make up the final performance category. That means change is coming to the heavy-duty diesel lubricants space. The introduction of a new category provides opportunities for enhanced lubricant performance in areas such as improved drain intervals, fuel economy and engine deposit protection. However, one major area of focus for next-generation lubricants will be greater protection and enablement of aftertreatment devices, helping heavy-duty OEMs comply with stringent new emissions standards set by the U.S. Environmental Protection Agency in 2022.
Rodgers, Zachary L.
Improving the Working Performance of Sliding Friction Pairs Using Optimal Asymmetric Textures04-18-03-001605/29/2025
Optimizing the parameters of asymmetric textures (AT) designed on the surface of sliding frictional pairs (SFP) can make each texture more reasonably distributed. Thereby, the oil film thickness can be more stable; and the lubrication and load ability of SFP can be improved. To clarify this issue, based on the SFP’s lubricating model added by AT using the rectangular structure, parameters of AT including the angle between the horizontal axe and bottom surface (φij), the angle between the lateral axe and bottom surface (γij), and texture’s depth (hij) are optimized. The study results show that the parameters of φij, γij, and hij of AT optimized can create the p (hydrodynamic pressure of liquid) better than the symmetric textures. Significantly, the pmax and load ability of the liquid in the SFP using optimal AT have been greatly increased compared to the liquid in the SFP using the symmetric textures. Accordingly, the results are an important reference for the design and distribution of
Wang, Cuifang, Zhang, Lu
Aviation Lubricant Tribology Evaluator (ALTE) Method to Determine the Lubricating Capability of Gas Turbine LubricantsARP6255A (Current)05/16/2025
Employing “ball-on-ring” philosophy, a nonrotating steel ball is held in a vertically mounted chuck and, using an applied load, is forced against an axially mounted steel rotating ring. The test ring is rotated at a fixed speed while being partially immersed in a lubricant reservoir. This maintains the ring in a wet condition and continuously transports a lubricating film of test fluid to the ball and ring interface. The diameter of the wear scar generated on the test ball is used as a measure of the fluid’s lubricating properties. The apparatus can be used by adjusting the operating conditions to reproduce two different wear mechanisms. Therefore, the ALTE can assess a lubricant’s performance in that regard. These mechanisms are described below.
E-34 Propulsion Lubricants Committee
Wear Protection for Electrified Transmissions Using e-Fluids without Active Sulfur04-18-03-001505/08/2025
In electrified drivetrains, lubricants are commonly in contact with the motor and other electrical components as well as the gears and bearings. Copper, present in these electrical components, is susceptible to corrosion by fluids containing active sulfur, which can lead to catastrophic failure of the unit. Lubricating fluids for electric vehicles (referred to as e-fluids) must not cause corrosion and must maintain high performance while having suitable electrical conductivity, material compatibility, and heat transfer properties. We describe a new formulation without active sulfur that has recently entered the market, which can protect against copper corrosion. We show that this e-fluid can provide suitable wear protection under field trial conditions, and that the e-fluid provides improved wear protection in bearing (FE-8) tests compared to a traditional extreme pressure axle fluid (API GL-4). Surface analysis (X-ray photoelectron spectroscopy) measurements of the component surfaces
Hopper, Elizabeth R., Williams, Megan S., Gahagan, Michael
Aerated Oil in the Rotating Channel03-18-03-001804/24/2025
In this article we examine the behavior of oil in the lubrication channel between the main bearing and the connecting rod bearing in the crankshaft of an internal combustion engine. The requirement for high service life and proper operation of these bearings, while minimizing input power of the lubrication system, lead to the need to understand the function of these structural parts in detail. To simulate and visualize this process, an experimental device was created. The device allows the experimenters to change individual parameters such as rotation speed, oil pressure, oil temperature, and aeration, while simultaneously visualizing the process with the help of a special rotating camera. These parameters are then obtained by image processing. In this way, the following influences are investigated here: at oil temperatures of 30, 50, and 80°C, relative oil pressures of 1, 2, 3, and 4 bar, at undissolved air in the oil of 5 and 10 vol% and crankshaft station speeds from 0 to 6000 1/min
Rychtar, Vaclav
Prediction of Pre-Ignition Borderline on Supercharged SI Engine by Livengood-Wu Integral2024-32-000804/18/2025
The LSPI (Low Speed Pre-Ignition) is one of the consecutive abnormal combustion cycles of supercharged SI engine with direct injection fuel supply system [1]. The LSPI occurs when the engine is running at low speed and high load condition. It is important for the SI engine to control essentially with alternative fuel, e-fuel and hydrogen in the future. It is considered that the LSPI would be caused by the autoignition of the deposit, the lubricating oil from ring crevice, the lubricating oil from piston crown and so on [2, 3, 4, 5]. Among of these causes, this research focuses on the scattering lubricating oil from piston crown. The previous our research has reported on the two points. One is about the frequency and quantity of the lubricating oil scattering from piston crown [6]. Another is about the frequency of abnormal combustion by the engine test [7]. As the result, it has been cleared that the frequency of abnormal combustion is 1/10 of scattering frequency of the lubricating
Omori, Takaya, Tanaka, Junya
Used Motor Oil Regeneration Efficiency of Type X Fly Ash–Based Zeolite Alone and Combined with Other Adsorbents04-18-03-001304/15/2025
This research article assesses the used motor oil’s (UMO) regeneration efficiency of a synthetic type X zeolite (siliceous fly ash–based) alone and combined with other adsorbents (composite adsorbents), namely activated carbon, bentonite, and acid-activated bentonite from Goshica’s (Kosovo) region. The UMO treated with the regenerating mixes has run about 20,000 km. Parameters including density, kinematic viscosity, viscosity index, pour point, and sulfur content were measured in the untreated and treated UMO and compared to those of the reference oil with additives of type SAE 5W-30. All regeneration mixes showed good regeneration efficiency, restoring the UMO’s parameters to almost the original ones of the reference oil with additives (SAE 5W-30). Only the zeolite alone could significantly reduce the sulfur content (removal efficiency 60%). This method deserves further investigation and with some improvements, it can be established as a reliable regeneration method for some UMO.
Korpa, Arjan, Dervishi, Sara, Gecaj, Diana, Shahu, Kristi, Shehu, Alma, Nuro, Aurel
Detecting Piston Ring–Cylinder Liner Metal–Metal Contact in a Fired Large Marine Diesel Engine Using Piezoelectric Transducers03-18-03-001704/09/2025
Shear-polarized ultrasonic sensors have been instrumented onto the outer liner surface of an RTX-6 large marine diesel engine. The sensors were aligned with the first piston ring at top dead center and shear ultrasonic reflectometry (comparing the variation in the reflected ultrasonic waves) was used to infer metal–metal contact between the piston ring and cylinder liner. This is possible as shear waves are not supported by fluids and will only transmit across solid-to-solid interfaces. Therefore, a sharp change in the reflected wave is an indicator of oil film breakdown. Two lubricant injection systems have been evaluated—pulse jet and needle lift-type injectors. The needle lift type is a prototype injector design with a reduced rate of lubricant atomization relative to pulse jet injectors. This is manifested as a smaller reduction in the reflected ultrasonic wave, showing less metal–metal contact had occurred. During steady-state testing, the oil feed rate was varied; the high flow
Rooke, Jack, Li, Xiangwei, Dwyer-Joyce, Robert S.
A Transient Friction Rig Capable of Showing Lubricant Differentiation Effects for High Pressure Fuel Pump Friction in Gasoline Engines; with Friction Comparisons Using the Same Engine Running a Standard Internal Combustion Engine Transient Cycle, alongside Two Types of Hybrid Electric2025-01-846704/01/2025
As the global energy transition moves to increased levels of electrification for passenger cars, then the number and role of hybrid electric vehicles (HEVs) increases rapidly. For these, the power reaches the road from an internal combustion engine (ICE) and/or an electric motor, with several switches between these three modes, over a typical drive-cycle. Consequently, this comes with a large increase in the number of significant engine stop and start events. Such events are potentially challenging for the HEV engine lubricant, as by comparison, for standard ICE cycles there is almost continuous relative movement of the two lubricated surfaces, for most areas of the engine. Based on both field and test cell observations, a challenging area for the lubricant within the gasoline direct injection (GDI) engine is the high pressure (HP) fuel pump, typically driven by a cam and follower, whilst lubricated by engine oil. From engine start, the speeds are low, also the fuel pump loads are high
Butcher, Richard, Bradley, Nathan, Lambert, Bertie
The Development of JASO GLV-2: Next Generation Specification for Ultra-High Viscosity Index Gasoline Engine Oils2025-01-846804/01/2025
Carbon neutrality has become a global initiative, prompting automobile manufacturers to introduce electrified vehicles such as HEVs, PHEVs, BEVs, and FCEVs. Although interest in BEVs is rising, HEVs, PHEVs, and other internal combustion engine vehicles are expected to remain in use in regions where transitioning to BEVs is challenging. For these vehicles, low-viscosity engine oil is a key measure to further reduce CO2 emissions. Moreover, high-efficiency engines in electrified vehicles typically operate at lower oil temperatures than conventional engines due to reduced thermal loss to coolant and oil. Lowering viscous resistance in the mid- to low-temperature range below 80°C is significant for improving fuel economy. However, viscosity must be maintained above a certain level to ensure the performance of hydraulic devices at higher temperatures. To achieve both characteristics, oils with a low temperature dependence of viscosity (ultra-high viscosity index) are required. This
Yamamori, Kazuo, Hirano, Satoshi, Yoshida, Satoru, Matsui, Noriyuki
A Study into the Engine Oil Performance on Plug-in Hybrid Electric Vehicles through an on-Road Fleet Test under Extreme Cold Environmental Condition2025-01-847104/01/2025
In pursuit of reducing carbon emissions and to fulfill the customers’ needs for fuel-saving and environmentally friendly cars, car manufacturers have been increasingly offering different choices of electrified cars to their customers. Among those different powertrain solutions, with a balance of energy source between on-board electricity and fossil fuels, plug-in hybrid electric vehicles (PHEV) are becoming a choice for more and more end users, particularly in regional car markets such as China in recent years. Owing to the diversified vehicle operating conditions, new challenges are brought to the engine oil to protect the hardware from issues such as piston deposit, water/oil emulsification, oil thinning caused by fuel dilution, stop-start bearing wear and corrosion. This technical paper seeks to understand the impact of different operating modes of PHEV on engine oil performance. One key finding is that extreme conditions were needed to accumulate water content in the oil. When the
Zhang, Ruifeng, Andrew, Rhiann, Martin, Etienne, Hu, Gang
Intebrake 3-D CFD Transient Simulation Studies for Predicting Flow Performance2025-01-836204/01/2025
This paper presents transient, complex, moving mesh, 3-D CFD analysis of an intebrake lubrication oil circuit for predicting flow performance. Intebrake is a mechanism for improving braking performance during over speeding conditions. The mechanism briefly opens the exhaust valve at the end of a compression stroke with a small valve lift and releases the compressed gases, thereby helping in quick application of the brake. There is no fueling during the process and hence, no combustion induced pressure rise which helps in quick application of the brake. During the intebrake operation, opening of the exhaust valve is achieved by using a complex lube oil circuit inside the exhaust rocker lever. The intebrake lube oil circuit consists of various spring-operated valves with micro-sized clearances, high oil pressure generation up to ~ 250 bar, 3-D movement of the mechanism components, and it is a transient operation. The 3-D movement consists of simultaneous rotational and translational
Tawar, Ranjit Ramchandra, Pasunurthi, Shyam Sundar, Bedekar, Sanjeev, Ranganathan, Raj
Reduced Order Model for Viscosity and Mass Density Sensing by A U-Shaped Wire2025-01-847204/01/2025
This paper focuses on the basic principle of measuring viscosity and density with U-shaped tungsten wire sensor, and develops a model for measuring liquid viscosity and density with the help of oscillating ball model. Firstly, the working mechanism of the wire resonator is deeply analyzed. Then, by reducing the order of the fluid dynamic function, a simplified model is established for measuring the viscosity and density of liquid with U-shaped tungsten resonator. The experimental results show that the maximum error of viscosity is 7.22% and the average error is 2.81% when the viscosity ranges from 4.526mPa.s to 62.01mPa.s. In the range of 0.8486g/cm3 to 0.8711g/cm3, the maximum density error is 7.00% and the average density error is 1.89%. In summary, the simplified model proposed in this paper can accurately measure the viscosity and density of liquids.
Shan, Baoquan, Shen, Yitao, Yang, Jianguo, Zhang, Zhaoying, Wu, Dehong, Zhao, Yingke
Engine Crankcase, Oil Pan and Lube System Multiphase CFD Analysis for Predicting Oil Aeration2025-01-836404/01/2025
This paper explains transient, computationally rigorous, three-dimensional and one-dimensional multiphase CFD analysis of engine oil drainback system and lubrication system for predicting aeration. Aeration of engine oil is an important factor as it affects working of Hydraulic Lash Adjusters, bearings performance and it reduces lube system pressure itself which is detrimental for the entire engine. In this work specifically effect of engine tilting on lube oil aeration is presented. When engine is tilted, crankshaft and connecting rod/s are dipped in to oil, which creates air bubbles. These air bubbles travel to lube pump and then to the engine lube system. Therefore, it is essential to model aeration in Engine crankcase, Oil pan and Lube system for the purpose of predicting oil pressure reduction in lube system. The problem under consideration is spread over a bigger zone, involves rotating and translating components, passage’s dimensions are varying from microns to meters and
Tawar, Ranjit Ramchandra, Bedekar, Sanjeev
Study of the Effects on Plain Bearings in Simulated Corrosion Tests Using Carbon Neutral Fuels2025-01-847004/01/2025
Many countries around the world are currently working toward carbon neutrality, which would reduce greenhouse gas emissions to net zero by 2050. To achieve carbon neutrality, the search for new fuels to replace gasoline has been active. This study focuses on hydrogen and methanol fuels and examines their effects on plain bearings when these fuels are used in internal combustion engines. Compared to gasoline, these fuels differ significantly in the composition of gases produced after combustion. It is assumed that nitric acid, etc. will be mixed in the engine oil when hydrogen is combusted whilst formic acid, etc. will be mixed in the engine oil when methanol fuel is combusted. For this reason, corrosion tests were conducted by adding nitric acid or formic acid solution to the engine oil then placing plain bearings in the deteriorated oil. The results confirmed that significant corrosion of the bismuth overlay coating occurred and subsequently the performance of plain bearings may
Kondo, Makoto, Kawaura, Hiroki, Shiroya, Tomoyasu, Watanabe, Airi
Numerical Comparison of TPMS Structures for the Design of an Automotive Engine Oil Cooler2025-01-815504/01/2025
Triply Periodic Minimal Surface (TPMS) structures offer the possibility of reinventing structural parts and heat exchangers to obtain higher efficiency and lighter or even multi-functional components. The crescent global climate concern has led to increasingly stringent emissions regulations and the adoption of TPMS represents a resourceful tool for OEMs to downsize and lighten mechanical parts, thereby reducing the overall vehicle weight and the fuel consumption. In particular, TPMS structures are gaining growing interest in the heat exchanger field as their morphology allows them to naturally house two separate fluids, thus ensuring heat transfer without mixing. Moreover, TPMS-based heat exchangers can offer countless possible design configurations. These structures are obtained by periodic repetitions in the three spatial dimensions of a specific unit cell with defined dimensions and wall thickness. By tuning their characteristic parameters, the structure can be tailored to obtain
Torri, Federico, Berni, Fabio, Martoccia, Lorenzo, Marini, Alessandro, Merulla, Andrea, Giacalone, Mauro, Colombini, Giulia
Effects of Lubricating Oil Consumption and Operation Duration on CO 2 Accumulation and Efficiency in an Argon Power Cycle Hydrogen-Fueled Engine2025-01-843604/01/2025
The trend of internal combustion engines is reducing or eliminating carbon emissions and improve the overall efficiency. The Argon Power Cycle hydrogen-fueled engine can specifically improve the thermal efficiency by employing argon as the working substance. At the same time, due to the utilization of hydrogen and oxygen, the combustion of the fuel in Argon Power Cycle hydrogen-fueled engines produces zero carbon emissions or NOx emissions. However, during engine operation, lubricating oil consumption can still generate CO2 and becomes the only source for carbon emissions. Furthermore, the accumulation of CO2 under closed cycle will impede the condensation recovery of argon and reduce the efficiency and power. In this study, a closed cycle model of Argon Power Cycle hydrogen-fueled engine was constructed, in which argon is recycled by condensation instead of being charged like air in an open cycle model. Effects of lubricating oil consumption and operation duration on CO2 accumulation
Wang, Chenxu, Li, Mo, SU, Xiang, Deng, Jun, Tian, Tian, Li, Liguang
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