IC Engine Research Articles

Effect of excess air ratio and ignition timing on performance, emission and combustion characteristics of high speed hydrogen engine

The main goal of automobile researchers is to develop internal combustion engines that are fuel efficient and emit zero pollutants. It can be inferred from prior research publications that lean burn conditions can significantly reduce emissions while improving engine efficiency. The lean-burn engine combustion temperatures are lower hence harmful emissions like NO are reduced. Gasoline fuels have a narrow equivalence ratio window hence it was necessary to evaluate the other alternative fuels with a wider equivalence ratio for using it in IC engines for better performance and fewer emissions. This experiment is conducted on a single-cylinder digital three-spark ignited electronic fuel injected (DTSI-EFI) single-cylinder, 4 stroke high-speed SI engine fuelled by hydrogen. The excess air ratios are changed and MBT timing was also optimized. Hydrogen has delivered the lowest emissions under lean conditions. This data gives guidelines for developing SI engines with hydrogen port fuel injection for meeting future emissions norms. This experimental attempt is to protect the environment from greenhouse gas (GHG) emissions. The highest Brake Thermal Efficiency (BTE) is recorded at the leaner condition (λ = 4) as 37.53%, the highest power output is 7.02 kW at λ=1.5. CO and THC emissions are absent in hydrogen fuel and NO emissions reduces towards lean combustion.

Heat transfer enhancement of the air-cooled engine fins through geometrical and material analysis: A review

Energy crisis and air pollution are the two leading scientific issues that require global attention. The fundamental reason for the rise in energy costs is the rapid depletion of fossil fuels which has raised fuel prices. Analysis of IC engines suggests thatthermodynamic constraints cause more than half of energy derived from fossil fuels to be lost to the environment. Prolonged working at high temperatures can alter an engine's performance and characteristics. One way of minimizing these losses is to regulate and keep the engine's temperature within the permissible range. Thus, cylinder blocks often include extended surfaces called finsto transfer away the heat from the engine surface. This study focuses on explaining the effect of variation in material, type, design, number of fins, and other parameters in improving fins' efficiency and enhancing the engine's performance. It has been observed that the optimum number of fins can significantly improve fin efficiency, and a 5% to 13% enhancement in heat transfer is possible through fin extension. Elliptical shape fins perform better than triangular and rectangular fins. However, circular and curved fins increase engine efficiency by reducing engine weight. Amongst various fin materials like Cast Iron, Copper, Magnesium, Aluminum, and its alloys, etc., more thermal flux has been observed for Aluminium Alloy 6082. Finally, authors have come to a conclusion that circular fins with holes and slots offer a higher heat transfer rate and improved engine performance at reduced material requirements. The circular fin geometry with slots and holes provides further scope of improvement by optimizing fin thickness, number of holes and slots, their dimensions and spacing to come with a combination that provides effective cooling along with ease of manufacturing in case of lightweight engines.

Adaptive system on engine misfire and knocking features for IC engine

Most countries in the world still rely on internal combustion engines as their daily means of transportation. The issue with internal combustion engines is irregularities in the combustion process that impact the environment, including misfiring and knocking. Numerous engineers and researchers have conducted studies to find solutions to this important engine problem to improve engine efficiency and achieve quality characteristics and customer satisfaction. The research aims to identify a workable integrated solution for the misfire and knocking features of an internal combustion engine. The RedLeo Pro V8 version 8.033 software was used to simulate the input data monitoring and control engine system. The engine condition was controlled by the Engine Control Unit (ECU). Data was collected using a vibration sensor and a wideband oxygen sensor. Low Processing program was used to represent data in two or three-dimensional graphs to determine the decision method. These signals were synthesized as adaptive system design signals to reduce noise and improve accuracy, enabling modification between normal and abnormal signals. As a result, the proposed method proves to be an effective method for engine fault diagnosis performed on the methodological paradigm of feature extraction and feature selection.

Review on Mono and Hybrid Nanofluids: Preparation, Properties, Investigation, and Applications in IC Engines and Heat Transfer

Nano fluids are widely used today for various energy-related applications such as coolants, refrigerants, and fuel additives. New coolants and design modifications are being explored due to renewed interest in improving the working fluid properties of heat exchangers. Several studies have investigated nanofluids to enhance radiator and heat exchanger performance. A new class of coolants includes single, binary, and tertiary nanoparticle-based hybrid nano-coolants using ethylene glycol/deionized water combinations as base fluids infused with different nanoparticles. This review article focuses on the hydrothermal behavior of heat exchangers (radiators for engine applications) with mono/hybrid nanofluids. The first part of the review focuses on the preparation of hybrid nanofluids, highlighting the working fluid properties such as density, viscosity, specific heat, and thermal conductivity. The second part discusses innovative methodologies adopted for accomplishing higher heat transfer rates with relatively low-pressure drop and pump work. The third part discusses the applications of mono and hybrid nanofluids in engine radiators and fuel additives in diesel and biodiesel blends. The last part is devoted to a summary of the research and future directions using mono and hybrid nanofluids for various cooling applications.

Comparison of turbo compounding technoligies on gasoline and diesel engines

This paper presents a parametric study and comparison of turbocompound gasoline engine with diesel engine based on analysis done in previous papers. Turbocompounding is an important technique to recover waste heat from engine exhaust and reduce CO_2 emission, improving fuel economy. By the time detected one of the biggest problems for IC engines is pollution. Downsizing studies are popular at the industry for the moments to get emission and fuel consumption decreased. Even if the racing industry gets involved in this trend having more efficient and more green racing vehicles is quite important for saving environment. Powertrain works with supercharged internal combustion engine by co-operation of two electric motors MGU-H (Motor-Generator Unit-Heat) and MGU-K (Motor-Generator Unit-Kinetic). It is also seen in passenger, light and heavy commercial vehicles with diesel engines using turbocompounding technology to decrease the pollution. The present paper compares the outcomes which were shown in previous papers and demonstrate the better performance in terms of greenhouse effect and pollution as well as engine power generation performance.

Experimental and CFD Investigation of Fuel Mixing in an Optical-Access Direct-Injection NG Engine and Correlation with Test Rig Combustion and Performance Data

The present paper is the result of a cooperation between Politecnico di Torino and AVL List Gmbh within a recent collaborative research project funded by the EC. The research work was focused on the experimental and numerical characterization of mixture formation, combustion, and emissions in direct-injection NG engines, to draw useful indication for the design of innovative, high-performance engine concepts. As a matter of fact, direct-injection IC engines running on NG are believed to be a competitive transition solution towards a sustainable mobility scenario, given their maturity, technological readiness, and flexibility with respect to the fuel quality. Moreover, gaseous-fuel engines can further decrease their carbon footprint if blending of natural gas with hydrogen is considered. Provided that mixture formation represents a key aspect for the design of direct-injection engines, the activity presented in this paper is focused on the characterization of NG injection and on the mixing process, as well as the impact these latter hold on the combustion process as well as on engine-out emissions. The mixture formation process was analyzed by means of combined CFD and optical investigations. Furthermore, a full version of the engine was tested on a dynamic test rig, providing quantitative information on the engine performance and emission characteristics. The CFD results highlighted the correlation between the mixture homogeneity and the combustion stability and hinted at a relevant impact of the jet characteristics on the air charge tumble and turbulence characteristics.

Tribological behavior of H-DLC and H-free DLC coatings on bearing materials under the influence of DC electric current discharges

In automotive industry, most of the moving components and lubricants are currently being reengineered in order to meet the much harsher operating conditions of electric vehicles (EVs). Diamond-like carbon (DLC) coatings have been widely used in automotive field mainly because of their lower friction and wear coefficients, high chemical inertness, corrosion resistance, and hardness. It is also possible that DLC coatings can afford very desirable tribological properties to the bearings and gears of electric vehicles. In addition, their superior dielectric properties could also be very ideal for such applications. In EVs, current leakages in the powertrain are very common and these can adversely impact the tribological behavior of bearings and/or other moving mechanical elements. Although DLC coatings provide superior tribological performance in IC engine applications, they have not yet been evaluated under electrified sliding conditions of EVs. In this work, two different types of DLC coatings (Hydrogenated DLC (H-DLC) and hydrogen-free DLC (H-free DLC) were produced on AISI 52100 steel substrates and tested using a ball-on-disc tribometer under non-electrified and electrified (DC, 3A) both dry and lubricated sliding conditions. Coefficient of friction (CoF), wear volumes, wear modes and mechanisms have been assessed and reported. The results showed that electrification can cause a decrease in CoF for baseline steel-on-steel contacts, but an increase for H-free DLC in lubricated condition. The change in CoF of H-DLC interface was negligible. However, electrification caused a significant increase in the wear volume of steel-on-steel and H-free DLC-coated surfaces, but little or no wear was observed for the H-DLC-coated cases in both dry and lubricated test conditions. Overall, the tribological behavior of H-DLC was almost unaffected by electrification, suggesting that one has to select the right kind of DLC for applications involving electrified contact conditions.

Evaluation of the variable valve timing strategy in a direct-injection hydrogen engine with the Miller cycle under lean conditions

The favorable physicochemical characteristics of hydrogen make it an excellent alternative fuel for IC engines. Compared with hydrogen port injection, hydrogen direct injection provides multiple degrees of freedom for injection strategies and mixture formation, which can effectively suppress abnormal combustion and enhance engine performance. Variable valve timing (VVT) and the Miller cycle, as advanced and effective means of improving engine performance, are less investigated based on a direct-injection (DI) hydrogen engine. Hence, to optimize the performance of a DI hydrogen engine, strategies of the Miller cycle and VVT are introduced. In this work, a 1.5 L direct-injection engine with a VVT system was employed to evaluate the effects of the Miller cycle, intake valve closing (IVC) timing, and exhaust valve opening (EVO) timing on the airflow exchange process, in-cylinder charge characteristics, heat release process, dynamics and emission characteristics. The engine speed was stabilized at 1400 rpm and the strategies of lean combustion and late injection were used. The main results are as follows. As the IVC timing is delayed, the ratio of pumping mean effective pressure to indicated mean effective pressure (PMEP/IMEP) first decreases and then slightly increases, and the engine tends to achieve a high level of brake thermal efficiency (BTE) when PMEP/IMEP is lower. The optimization of intake and exhaust VVT can shorten combustion duration and reduce cyclic variation by increasing volumetric efficiency and improving mixture distribution at ignition timing. Furthermore, the engine reaches 42.22% BTE and a high level of brake mean effective pressure by the cooperative control of IVC and EVO timing. NOx emissions can be controlled below 100 ppm by employing the synergistic effect of the Miller cycle and VVT. It is worth mentioning that exhaust VVT as a way to compensate for the performance of the DI hydrogen engine with the Miller cycle should not be ignored.

Advanced combustion strategies for improving ic engine efficiency and emissions

The growing need for higher fuel efficiency and compliance with increasingly stringent emission regulations has prompted significant advancements in internal combustion (IC) engine technology. Traditional combustion methods, while widely utilized, face inherent challenges such as limited thermal efficiency and the production of harmful emissions like nitrogen oxides (NOx), particulate matter (PM), carbon monoxide (CO), and unburned hydrocarbons (HC). To address these concerns, researchers and engineers have developed a range of advanced combustion strategies that offer the potential to drastically improve engine efficiency while minimizing environmental impact.This paper provides a comprehensive analysis of cutting-edge combustion techniques, with a focus on strategies that balance the trade-off between fuel efficiency and emission reduction. Prominent among these strategies is Homogeneous Charge Compression Ignition (HCCI), which utilizes a lean, premixed air-fuel mixture to achieve spontaneous ignition at low temperatures, significantly reducing NOx and PM emissions. Another promising technique, Reactivity-Controlled Compression Ignition (RCCI), leverages the controlled use of two fuels with different reactivity levels, enabling precise control over the combustion process and enhancing both fuel efficiency and emission control. In contrast, Gasoline Direct Injection (GDI) technology improves fuel atomization and combustion control by injecting fuel directly into the combustion chamber, leading to higher efficiency and power output, albeit with challenges related to particulate emissions.In addition to these combustion strategies, this paper explores the role of Low-Temperature Combustion (LTC), which operates at reduced in-cylinder temperatures to mitigate the formation of NOx and soot, as well as the potential of advanced ignition systems like plasma or laser-based ignition to improve lean-burn combustion processes. Furthermore, the paper examines the integration of renewable fuels, such as hydrogen and biofuels, with advanced combustion techniques to support the global transition toward cleaner energy.The analysis also considers technological enablers such as variable valve timing (VVT), turbocharging, and sophisticated exhaust after-treatment systems that complement these advanced combustion strategies. Moreover, the application of simulation and optimization tools, including computational fluid dynamics (CFD) and machine learning (ML), is highlighted as essential for refining engine design and optimizing combustion processes.Despite the notable progress, challenges remain in terms of system complexity, control precision, and expanding the operational range of these advanced combustion techniques. As the automotive industry moves towards electrification and hybridization, advanced IC engine combustion strategies will continue to play a crucial role in improving vehicle performance and sustainability. This paper concludes by outlining the future prospects for further optimizing combustion efficiency and integrating renewable fuels in next-generation IC engines, thereby contributing to a cleaner, more efficient transportation sector.

Ammonia and hydrogen blending effects on combustion stabilities in optical SI engines

Ammonia is a promising energy carrier and carbon-free fuel, which is getting more attention today when fossil energy is increasingly exhausted. However, ammonia combustion in the IC engine suffers from combustion instabilities and misfiring issues. Hydrogen is also carbon-free energy and can be directly obtained by ammonia catalytic reforming. The addition of a small amount of hydrogen can effectively alleviate the weakness of ammonia combustion, while ammonia and hydrogen blending effects on combustion stabilities and their critical conditions remain unclear. In this work, the effects of hydrogen addition on ammonia combustion characteristics were experimentally investigated in an optical SI engine with high compression ratios. The results show that the indicated thermal efficiency first increases and then decreases with the elevation of hydrogen-ammonia energy ratios (χ), with an optimal value at χ≈7.5 %. Further hydrogen addition can aggravate indicated thermal efficiency due to the large heat transfer loss caused by high-temperature hydrogen combustion. Combustion visualizations show that there is a critical threshold of hydrogen-ammonia energy ratio (χ=10.0–12.5 %), around which engine combustion characteristics are changed significantly. When χ < 10 %, the effect of hydrogen addition on the ammonia flame speed becomes more pronounced since the hydrogen substantially improves the stability of the early-stage combustion. When χ > 12.5 %, hydrogen shows an obvious influence on the initial flame formation of ammonia, which is attributed to the low flame stretch sensitivity, facilitating early flame development. In addition, flame propagation when χ < 10 % is more sensitive to temperature than flame propagation with χ > 12.5 %. The current research demonstrates that proper ammonia-hydrogen energy ratios are important for stable combustion and thermal efficiency improvement.

Investigation and Study of Ammonium Hydroxide and Biodiesel Blend as an IC Engine Fuel

The use of conventional fossil fuel has resulted in global warming. Biodiesel is a substitute fuel obtained from vegetable oil by transesterification process which can replace conventional diesel. Good alternative to traditional hydrocarbon-based fuel is ammonia combined with a biofuel. Ammonia is free of Carbon and can be extracted from sustainable renewable energy sources. It can be used with slight modifications on current IC engines. However running the engine on pure ammonia poses a lot of challenges which needs to be tackled. Running the engine on Biodiesel results in slightly more NOx emission, compared with traditional fuel. In the present study an experimentation has been carried out to examine the effect of biodiesel and ammonium hydroxide blend on ICE performance, emission and combustion aspects, in terms of specific fuel consumption, brake thermal efficiency, Nitrogen oxides (NOx) and Hydrocarbon (HC), Carbon monoxide (CO) and Carbon dioxide emissions. Biodiesel blends are examined using a single cylinder four stroke Kirloskar ICE. Experiments have been performed with varying percentages of ammonium hydroxide (3%, 6%, 9%) and B50 (50% diesel and 50% Karanja biodiesel) blended with Diesel and then compared with base line conventional diesel. This paper will help in understanding how percentage variation in ammonium hydroxide and biodiesel blend will effect emission and performance.&#x0D;

Investigate The Effects of Intake Air Temperature on The Performance and Emissions of The IC Engine Fuelled by Biodiesel B30

The study included the use of biofuel to reduce the percentage of environmental pollution caused by other environmentally polluting fuels that used in other studies. The current study presents investigations of CI engine performance and emissions at various engine speeds under constant engine load. The fuel under consideration in this work is biodiesel B30. A 2.4-liter, 16-valve, 4-cylinder engine with a compression ratio of 15.5:1 is used. Various inlet air temperatures (10 to 35°C with an increment of 5 degrees) are chosen to study their effects on engine performance and emissions. The results show that increasing the inlet air temperature increases brake explicit fuel feasting (BEFF) beside to nitrogen oxide (NOx), while decreasing the brake power and torque. In this scientific revision, a tentative analysis was conducted on a CI engine at various engine speeds and inlet air temperatures., The results were obtained at engine speeds of 2100 rpm at various engine loads and revealed an increase in BSFC of biodiesel blends (B20, B50, and B100) as injection pressure was increased.

Prediction of the emission characteristics of biogas as a supplementary fuel in SI engines using CFD to assess its applicability

This study investigates the potential for the utilization of biogas as a supplementary fuel in a SI engine by studying the emission characteristics of a biogas-fuelled engine using computational fluid dynamics(CFD). Biogas is generated using a lab-scale floating drum bio digestor coupled to a SI engine to produce power. To determine the emission characteristics, the bio-digester and the combustion chamber of the SI engine with the desired specifications are modelled using the CREO software, and further Computational analysis is carried out using ANSYS FLUENT software. Emission parameters like Carbon monoxide (CO), Carbon dioxide (CO2), and Nitrous oxide (NOx) have been simulated for the SI engine utilizing biogas and gasoline. Computational results show that the bio-gas-operated SI engine shows less emission than gasoline. The results show that the CO emission decreased from 0.004 ppm to 0.035 ppm in gasoline and biogas modes, respectively. Also, the CO2 decreased from 0.021 ppm to 0.0052 ppm. The concentration of nitrous oxides in the emission shows a drastic decrease from 0.1343 ppm to 0.0234 ppm in gasoline and biogas mode. The significant reduction in emission characteristics when utilizing biogas as a fuel in SI engines against gasoline makes biogas an appealing fuel option for IC engines. applications.

Neem-castor seed oil esterification modelling: Comparison of RSM and ANFIS

Even though the desirable fuel properties and enhanced engine characteristics of an IC engine have led to the adoption of hybrid second generational oily feedstock (HSGOF) over a mono-oily feedstock, the high FFA associated with the HSGOF remains a challenge. The Response Surface Methodology (RSM) and Adaptive-Network-based Fuzzy Inference System (ANFIS) were used to model the esterification of neem and seed crude oils (NCSO) with a high free fatty acid content (FFA). The RSM and ANFIS were used to model and optimize input: esterification variables such as NCSO ratio (20–40), catalyst dosage (1.0–2.0 wt%), retention time (1.5–2.5 h), and NCSO/methanol molar ratio (4.5–5.5) to achieve the lowest FFA for the NCSO esterification process and produce composite biodiesel. Optimum acid value (AV) of 2.1 mg KOH/g was attained at NCSO ratio of 20, catalyst dosage of 2 wt%, retention time of 2.0 h, and molar ratio of 4.5. A contrast of the developed models was accomplished by statistical norms such as coefficient of determination (R2), root mean square error (RMSE) with standard Error of Prediction (SEP). The R2 of 0.82522, RMSE of 0.68099, and SEP of 0.21729 for the RSM model (RM) related to the R2 of 0.9982, RMSE of 0.02434, and 0.01992 for the ANFIS model (AM). The AM seems more consistent than the RM in pre-treating and rendering high NCSO for composite biodiesel production. The key fuel properties of the neem-castor oil methyl ester (NCSOME) certified with those of biodiesel international standards.

Study and Performance Characteristics of Gasoline Direct Injection Engine Using Alternative Fuels

Abstract: Biogas is the one of the best alternative fuel for IC engines. However some improvements and different techniques are still needed. In this research biogas with petrol fuelled Gasoline Direct Injection (GDI) engine performance was to be studied. The current study shows that biogas with petrol using GDI engine, particularly beneficial to reach interesting conversion efficiencies. It allows a significant boost in energy conversion from biogas compared to existing system.

Microscopic study of EPS-infused biodiesel with DEE and its performance and emissions in a diesel engine

The main objective of this study is to investigate some important fuel properties of expanded polystyrene (EPS)-infused biodiesel blends without and with the addition of a certain percentage of diethyl ether (DEE), a cetane number (CN) enhancer. The originality of this study is the use of high-CN DEE as an additive for EPS-infused canola biodiesel to investigate a diesel engine’s performance and emissions. Furthermore, we performed a microscopic study (of structure and particle size distribution) of EPS-infused canola biodiesel blends without and with DEE as an additive. Biodiesel is an effective solvent for EPS. EPS-infused biodiesel can be used in diesel engines for power production, and it can be a supplementary energy source for IC engines. This study investigates the EPS-infused biodiesel blend performance and emission in a direct injection (DI) diesel engine at low, medium, and high loads, each at 1000, 2100, and 3000 rpm. The EPS was dissolved in biodiesel at varying concentrations (2, 6, and 10 g/L) at room temperature (25 °C). The results for different EPS-infused biodiesel blends are compared with those of pure diesel and biodiesel, and EPS dissolution and performance improvements with DEE were achieved.

Design and Fabrication of Solar Powered Three Ways Grass Cutter

The grass is mowed uniformly using a solar-powered grass cutter. Future power usage will be substantial. With it, lawns at parks, colleges, schools, and other locations are maintained and taken care of. The highly fine and uniform surface appearance of the lawn is easily operated and maintained by untrained individuals. Modern grass-cutting equipment is becoming increasingly widespread. Our daily lives show us how man-made pollution works. Older lawn cutter models had IC engines, which were bad for the environment and increased pollutants. An IC engine-driven cutter is more expensive. Such commonplace machinery needs considerable upkeep. We plan to develop a new type of solar-powered lawn cutter that is more affordable than the one now in use to get past these problems. Solar energy is the term used to describe the heat and light radiations that we receive from the sun. It is among the most widely used and diverse non-conventional renewable energy sources available on a global scale. It is devoid of contaminants, enters the market right away, and has no value. The use of equipment like star panels, which are constructed of electrical phenomenon cells, to produce electricity and power from solar energy. This year, solar system has drawn more attention because of its advantages over other renewable energy sources. The demand for and requests for green energy technology derived from renewable energy sources are increasing. The Solar Grass Cutter is a mechanical device that cuts grass with the usage of electricity. Its body is first constructed from PVC pipe, square shape plywood and caster wheels are then positioned under the body of the square plywood. Then, an inclined fibre plate is set on a body with a solar panel attached to it. That transmits solar energy, which is changed into electrical energy, which is changed into mechanical energy at the end of electric motor shaft, which contain the blade setup to cut the grass.

A Comprehensive Study of the Effects of Various Operating Parameters on a Biogas-Diesel Dual Fuel Engine

Alternative fuels are found to be the most promising solution to the problem of conventional IC engine pollution because their use curtails its huge emissions without exerting a negative impact on its performance. In this research, a conventional compression ignition engine is investigated by operating it with the combination of simulated biogas and neat diesel under a dual fuel mode of operations. The simulated biogas in the current work comprises different proportions of methane and carbon dioxide in the mixture. The full factorial approach in this work involved studying the effects of parameters such as biogas flow rate, composition, intake temperature, torque, and methane enrichment (complete removal of CO2 from biogas) on the engine performance, emissions, and combustion indices with an extensive number of experiments. It is witnessed from the research that biogas is capable of providing a maximum of 90% of the overall energy input, while the CI engine operates under dual fuel mode. Under the dual fuel mode of operation involving biogas, a significant amount of reductions are witnessed in secondary fuel consumption (67%), smoke (75%), and NOx (55%) emissions. At low flow rates, biogas is found to improve brake thermal efficiency (BTE), whereas it reduces hydrocarbon and carbon monoxide emissions. Methane enrichment resulted in more diesel substitution by 5.5% and diminishes CO and HC emissions by 5% and 16%, respectively. Increasing the intake temperature caused an increase in thermal efficiency (2%) and a reduction in diesel consumption (~35%), and it curtailed all emission elements except NOx.

Mechanical modeling and design of YSZ ceramic coated piston for effective performance in an IC Engine

Mechanical modeling and design of YSZ ceramic coated piston for effective performance in an IC Engine

Effect of Zero-Sap Antiwear/Ep Lubricant Additives on Nano-Mechanical Properties of Tribofilms Formed on AISI 52100 Steel Grade

Numerous nations have recently passed stricter environmental legislation due to excessive release of harmful emissions like sulfur (S), phosphorus (P), and zinc (Zn) in conventional lubricating oil additives used in contemporary internal combustion engines. Use of borate ester lubricant additives with no sulfated ash, phosphorus, or sulfur effect (zero-SAPS) is one way to reduce this effect. The resistance of tribofilms from oils containing borate esters on AISI 52100 steel grade to plastic deformation is not entirely understood, yet. This study compares Zinc Dialkyl Dithiophosphate (ZDDP) to the tribological performance and Nano-mechanical behavior of tribofilms made from each of the antiwear/extreme pressure borate esters in Polyalphaolefin (PAO6) base oil. According to tribological test findings on a reciprocating steel pin-on-steel plate sliding rig, the boundary films formed by the borate esters reduced friction and wear in a manner similar to that of ZDDP. On the wear scar, the Nano-indentation technique was used to characterize the Nano-mechanical properties of the tribofilms. The ratios of reduced elastic modulus to hardness (E’/H) for the tribofilms of both borate esters are not only higher than the steel substrate but also comparable to ZDDP. This shows that boron-containing tribofilms offered ZDDP-like tribological performance and also have the ability to release absorbed frictional energy when moving across elastic asperity contacts. Consequently, using borate additives in lubricating oils in IC engines is a method of reducing exhaust emission modern vehicles without adversely affecting tribological performance.Key Words:Anti-wear Additives, Borate Esters, Plasticity Index.