Abstract The progressive exhaustion of conventional fossil-fuel reserves, combined with increasingly stringent emission legislation under Euro 6 and Bharat Stage VI (BS-VI) norms, has created an urgent imperative to develop and validate alternative fuel pathways for spark-ignition (SI) engines. This paper presents a rigorous experimental investigation of the performance and emission characteristics of a four-stroke, four-cylinder water-cooled petrol engine fuelled with four configurations: neat gasoline (baseline), 10% ethanol–gasoline blend (E10), 20% ethanol–gasoline blend (E20), and a compressed natural gas (CNG) pilot blend. Dynamometer tests were conducted at 1500 rpm across four discrete load conditions (25%, 50%, 75%, and 100% of rated load). Measured performance parameters include Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC), Mechanical Efficiency, and Volumetric Efficiency. Exhaust emission constituents—HC, CO, CO₂, and NOₓ—were quantified using a calibrated five-gas analyser in accordance with ISO 8178. The Morse test was used to determine Indicated Power independently for each cylinder. Results demonstrate that E20 achieves the highest BTE of 33.2% at full load, a 10.3% relative improvement over the petrol baseline (30.1%), with BSFC concurrently reduced from 275 g/kWh to 245 g/kWh. HC emissions decrease by 27.6% and CO by 31.6% with E20, while NOₓ rises marginally by 7.2%. CNG blend delivers the lowest CO (1.68% vol) and NOₓ (810 ppm) but at a volumetric efficiency penalty. Uncertainty analysis confirms BTE values within ±1.32% at 95% confidence. E20 is substantiated as a viable drop-in alternative fuel requiring no hardware modification, aligned with India's EBP 2025 mandate. Index Terms alternate fuels, brake thermal efficiency, BSFC, CNG, ethanol blends, exhaust emissions, four-cylinder engine, SI engine.

Objective This study aimed to investigate the role of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling cascade in the inflammatory responses induced by whole gasoline engine exhaust (GEE) in lung epithelial cells via air-liquid interface (ALI) exposure. Materials and methods Using an ALI exposure system, human bronchial epithelial cells (BEAS-2B) and type II alveolar epithelial cells (A549) were exposed to whole GEE collected from a two-wheeled motorcycle at various dilution ratios. After a 1 h exposure at 10 mL/min, cell relative viability, intracellular reactive oxygen species (ROS), glutathione (GSH), oxidized glutathione (GSSG) and the GSH/GSSG ratio were measured. Inflammatory cytokines (IL-1β, IL-6, and IL-8) were quantified. The Nrf2 inhibitor brusatol (BR, 300 nM) and the antioxidant N-acetyl-L-cysteine (NAC, 5 mM) were used to modulate the Nrf2/HO-1 pathway and oxidative stress, respectively. Protein and gene expression levels were analyzed by Western Blotting and real-time PCR. Results Exposure to 10%GEE induced oxidative stress and optimally activated Nrf2/HO-1 expression without cytotoxicity, while higher concentrations suppressed this signaling pathway. Significant correlations were observed between Nrf2/HO-1 levels and inflammatory cytokines. Inhibition of Nrf2/HO-1 with BR reduced inflammatory responses which induced by the 10%GEE in both BEAS-2B and A549 cell lines. Furthermore, attenuating oxidative stress with NAC inhibited both Nrf2/HO-1 expression and the GEE-induced inflammatory response. Conclusion Inhibiting the Nrf2/HO-1 signaling cascade attenuates the pro-inflammatory response induced by GEE in lung epithelial cells following ALI exposure. The Nrf2/HO-1 pathway appears to be a critical regulator of GEE-induced pulmonary inflammation, highlighting its potential as a therapeutic target.

Research on low-frequency hydrocarbon injection control strategy and NOx removal performance of TWC + NSR coupling system for lean burn gasoline engines

In-cylinder pressure is a key parameter for evaluating combustion processes and engine performance in spark-ignition engines. However, acquiring high-resolution pressure data over a wide range of operating conditions, particularly under varying spark advance (SA), is costly and technically challenging, which limits its practical application. To address this issue, this study proposes two artificial neural network (ANN)-based methods for in-cylinder pressure reconstruction using data from a three-cylinder gasoline engine under different spark advance conditions. Both methods employ crank angle and spark advance as input features. The first method (ANN-P) directly predicts the in-cylinder pressure profile, achieving a coefficient of determination (R2) exceeding 0.99 on both training and validation datasets, with a root mean square error (RMSE) below 0.13 bar. The model accurately reproduces the pressure evolution throughout the compression, combustion, and expansion processes and enables reliable estimation of indicated mean effective pressure (IMEP). The second method (ANN-HRR) adopts an indirect strategy by first predicting the heat release rate (HRR) and subsequently reconstructing the pressure trace through thermodynamic integration based on a single-zone model. This approach avoids error amplification associated with numerical differentiation and demonstrates improved accuracy in predicting combustion phasing metrics, such as CA10 and CA50. The results indicate that both methods effectively capture the influence of spark timing on combustion characteristics and peak pressure. While ANN-P provides higher accuracy in pressure reconstruction, ANN-HRR offers superior performance in characterizing combustion features. Overall, this study presents a cost-effective and accurate framework for combustion diagnostics, performance calibration, and control optimization of gasoline engines.

As part of efforts to support the transition toward a zero-carbon future, this research evaluates how the use of natural gas and liquefied petroleum gas under lean burn conditions affects the energy efficiency and environmental outcomes of a diesel engine that has been retrofitted to operate with spark ignition. The assessment of the ecological potential of these low-carbon gaseous fuels was performed at the engine test bed at optimum spark advance set from the condition of achieving maximum brake thermal efficiency (i.e., lowest carbon dioxide emission, CO2). The results found with lean mixtures are compared to those obtained under stoichiometric conditions, as well as to those from a commercial gasoline engine of comparable size, equally operated at stoichiometry. With lean burning, a clear improvement is observed for all operating points in terms of brake thermal efficiency with respect to the stoichiometric operation. The results highlight a slightly greater improvement when operating with natural gas lean mixtures: between (1.35 and 2.35) percentage points gained in this case, compared to (1.15–2.10) percentage points gained in the case of liquefied petroleum gas. As for CO2, a maximum 28% reduction when using natural gas is achieved with lean operation with respect to the commercial gasoline engine. Using lean mixtures also brings an important reduction in the engine-out pollutants (carbon monoxide, nitric oxides and particulate number). However, with respect to stoichiometric operation, cyclic variability of the prototype degrades with lean burning but remains lower than one of the baseline commercial gasoline engines.

Retrofitting existing internal combustion engine vehicles to operate on cleaner fuels offers a practical pathway toward reducing urban emissions during the transition to sustainable mobility. This study experimentally investigates the feasibility of converting a 796cc Maruti Alto multi-point fuel injection (MPFI) spark-ignition engine to operate exclusively on compressed natural gas (CNG) without petrol as a pilot fuel. The influence of iridium spark plug electrode gaps (0.5, 0.6, and 0.8mm) on ignition stability, engine performance, and exhaust emissions was evaluated using a computerized test bench equipped with an eddy current dynamometer. Experimental results indicate that the 0.6mm electrode gap provides the most stable combustion and minimum misfire tendency under lean CNG operation. Compared with conventional petrol operation, carbon monoxide (CO) and hydrocarbon (HC) emissions decreased by approximately 42% and 38%, respectively, while brake power declined by about 4-5% due to the lower energy density of gaseous fuel. ANOVA analysis confirmed the statistical significance of these variations (p < 0.05). The results demonstrate that optimized ignition parameters enable stable CNG-only operation in compact MPFI engines, supporting engine retrofitting as a cost-effective strategy for cleaner urban transportation.

Pounded yams are a popular traditional dish in Sub-Saharan Africa, typically prepared using a labor-intensive mortar and pestle method. Although electric yam-pounding machines are available, their dependence on electricity limits their applicability in off-grid rural communities. This study presents the design and performance evaluation of a cost-effective petrol-powered yam pounding machine constructed using locally sourced materials. The prototype consists of a stainlesssteel pounding chamber, belt drive system, shaft, rotor, and gasoline engine. Performance evaluation demonstrated high operational efficiency ranging from 97% to 99.67%, particularly when larger yam masses were processed with shorter processing times. Regression analysis (R² = 0.99) indicated that yam mass significantly influenced pounding efficiency, texture, and lump formation. Nutritional and microbial analyses confirmed that the machine-processed yam maintained acceptable nutritional quality and hygienic safety. Sensory evaluation further indicated a higher preference for machinepounded yam compared with the traditionally prepared product. Overall, this innovation provides a practical and scalable solution for rural communities, improving food processing efficiency while preserving the cultural importance of pounded yams.

Emission and combustion performance of anhydrous ethanol jet ignition in an optical single-cylinder gasoline engine

Environmental concerns have increasingly driven industries worldwide, particularly the automotive sector, to address the challenges posed by pollutant emissions from internal combustion engines. Diesel engines, for instance, offer higher thermal efficiency than gasoline engines but remain major contributors to atmospheric pollution. Their emission characteristics are also strongly influenced by fuel properties. One promising approach to mitigating these emissions is the use of gasoline–diesel fuel blends. Due to their higher volatility and improved vaporization behavior, these blends promote more homogeneous air–fuel mixture formation, making them suitable for compression ignition engines. In addition, modifying key combustion parameters, most notably injection timing, has proven effective in influencing both emissions and combustion dynamics. Alongside injection pressure and intake oxygen concentration, injection timing plays a critical role in determining pollutant formation and the acoustic characteristics of the combustion process. This study examines the impact of a gasoline–diesel blend (G10) on the performance and emission characteristics of a diesel engine, with particular emphasis on the effects of varying injection timing. The aim is to experimentally evaluate how combining this blend with injection timing adjustments influences engine efficiency and emission output. The experimental results show that advancing injection timing improves torque, power output, and thermal efficiency while maintaining relatively low fuel consumption. Conversely, retarding injection timing is more effective in reducing pollutant emissions. The most effective strategy is delaying injection at 80% load and 3,500 rpm, which results in reductions of smoke density, NO X , and CO 2 by 77.34%, 34.45%, and 11.34%, respectively. Performance also improves, with torque increasing by 26.25%, power by 14.52%, and specific fuel consumption decreasing by 9.76%. Although a trade-off exists between optimizing performance and minimizing emissions, the findings indicate that strategic calibration of injection parameters can achieve a balanced compromise between both goals. In conclusion, adjusting injection timing emerges as a viable technique for reducing pollutant emissions without significantly compromising—and potentially even enhancing—engine performance.

In this study, the effect of boron carbide (B4C), hexagonal boron nitride (hBN), holy super graphene (HSG), and hybrid (B4C + hBN + HSG) nano-additives on the tribological performance of SAE 5W-30 gasoline engine oil was investigated on Al-Si-based samples (Al 4032) prepared by cutting from a single-cylinder gasoline engine block. The addition of nano-additives regularly increased the kinematic viscosity; the 63.80 mm2/s (BO) value rose to 68.90 mm2/s at the highest level of B4C and to 70.50 mm2/s in the hybrid oil (≈10.5% increase). The lowest and most stable friction performance was found in the hybrid 0.025 g/25 mL nano-additive oil, which remained between 0.03 and 0.05 during the entire COF test. The EDS mapping and line scan results confirmed the formation of tribofilm by identifying the additive elements (B for B4C, B and N for hBN, C for HSG) in the wear scar, and the presence of increased O elements showed the restricted formation of tribo-oxidation. The results show that hybrid nano-additive oils provide the most effective friction and wear improvement, especially at low concentrations, while at high additive levels, performance does not show a consistent increase due to particle accumulation and third-body effects.

The Influence of Convective Heat Transfer in the Turbine Performance Analysis of a Variable Geometery Turbo Charger for a Gasoline Engine

Various countries are accelerating their energy transitions due to rising greenhouse gas emissions driving global climate change. The COP26 Conference set targets to limit global temperature rise to below 1.5 °C by 2030 and achieve net-zero emissions by 2050. Hydrogen is considered a promising alternative fuel because it produces only water vapor emissions and reduces dependence on fossil fuels. This study aims to analyze the effect of hydrogen gas, produced through electrolysis, mixed with Pertalite fuel on the performance of an internal combustion engine. The electrolysis process employed an Alkaline Electrolyzer Cell of the wet cell type, using a 30%wt NaOH electrolyte, a 12V power supply, and current variations of 40 A and 50 A. Engine performance parameters were evaluated under a brake load of 0.25 kg/cm². The results showed that at 40 A, the highest HHO gas production rate reached 0.9 Lpm, resulting in a 15.3% increase in effective shaft power, 5.7% thermal efficiency, 6.7% volumetric efficiency, 1.1% AFR, and a 29.06% reduction in BSEC. At 50 A, HHO gas production also reached 0.9 Lpm, with improvements of 18.3% in effective shaft power, 8.6% thermal efficiency, 10.8% volumetric efficiency, 2.84% AFR, and a 40.7% reduction in BSEC. These findings confirm that hydrogen blending enhances engine performance while supporting emission reduction.

In the Latin American Pacific region, rivers are the primary transportation routes for isolated and non-interconnected areas; however, river transport relies heavily on fossil fuels, resulting in high operating costs, CO2 emissions, and energy dependence. To address this challenge, this study proposes a methodology for the optimal sizing of renewable-based charging stations specifically adapted to the environmental and operational conditions of the Colombian Pacific coast. This research fills a critical gap in the literature by moving beyond urban-centric charging models and simplified theoretical assumptions, instead integrating real river navigation data with technical modeling of electric boat energy consumption. The methodology evaluates the technical, economic, and operational performance of photovoltaic and hybrid photovoltaic–hydrokinetic microgrids designed to ensure reliability under the region’s extreme resource seasonality and bimodal pluvial regime. Results indicate that while purely photovoltaic systems offer lower initial investment costs, hybrid configurations significantly enhance energy resilience by leveraging complementary renewable sources during periods of low solar irradiation. Crucially, the transition to electric propulsion reduces annual CO2 emissions by more than 98%, mitigating approximately 3421 kg per vessel compared to conventional 20 HP gasoline engines. A comparative analysis shows that the 1.1 kW electric boat is a cost-effective solution, with a 1.76-year return on investment. In contrast, the 4 kW model offers operational performance comparable to conventional gasoline boats, with a 4.95-year payback. This study provides a foundational framework for sustainable mobility in high-vulnerability territories by adapting technological solutions to site-specific environmental realities.

Abstract The current scarcity of fossil fuels requires the use of alternative fuels in motor fuels, especially diesel engines and gasoline engines. One of the alternative fuels used in plant-based internal combustion engines is biodiesel fuel produced from palm oil. A comprehensive analysis is needed with the use of crude palm oil (CPO) biodiesel fuel because it still causes decreased diesel engine performances. The purpose of this study was to determine the impact of using crude palm oil biodiesel fuel on performance of diesel engine. The research method was carried out experimentally on a diesel engine by comparing the performance of engines using pure biodiesel (B100) and biodiesel (B30) fuels from CPO fuel and compared with diesel fuel (B0) as a control parameter tested by varying the engine loads. The results showed that pure biodiesel fuel (B100) can be used in diesel engines, especially in biodiesel fuel (B30) even though the engine performance is still below diesel fuel (B0). This is marked by the power of 4.24 kW and torque of 19.83 Nm at a high engine load. The use of biodiesel fuel also causes reduced thermal efficiency and increased specific fuel consumption (SFC).

Enhancing engine reliability with machine learning techniques on spark plug deposition using green alcohol blend fuels on gasoline engine

Enhancing in-cylinder flow dynamics through a variable tumble mechanism: A synergistic approach to improve combustion efficiency in unthrottled gasoline engines

Performance enhancement of a single-cylinder gasoline engine through hydraulic variable valve actuation (HVVA) system integration

Simulation of a gasoline engine to evaluate the performance and thermal efficiency using different gasoline fuels

Effects of flame propagation direction and in-cylinder flow enhancement through combustion chamber design on knocking characteristics in a direct-injection turbocharged gasoline engine

Sago is a local food resource with high potential to be developed as an alternative carbohydrate source in Indonesia. One of the critical stages in sago processing is the grating process, which significantly affects production capacity and efficiency. This study aims to analyze the effect of the number of grating teeth on the performance of a sago stem grating machine. Two grating tooth variations, namely 18 × 20 and 20 × 22, were tested using a 7.5 HP gasoline engine. Each variation was tested three times using sago stems weighing 6,000 grams. The observed parameters included grating time, mass of perfectly grated material, imperfect grated material, wasted material, production capacity, and production efficiency. The results showed that the 20 × 22 grating teeth variation produced better performance, with a production capacity of 128.85 kg/h and an efficiency of 94.70%, compared to the 18 × 20 variation with a capacity of 99.65 kg/h and an efficiency of 89.3%. The study concludes that increasing the number of grating teeth significantly improves the performance of the sago stem grating machine.