Spark Ignition Engine Research Articles

Effects of charge motion on knock and thermal efficiency under high load condition of a heavy-duty natural gas engine

Nowadays, the carbon-neutral trend and the crude oil crisis have brought natural gas into increasing focus. However, heavy-duty engines fueled by natural gas have been plagued by thermal efficiency and knocking limitation problems. Well-structured charge motions can enhance thermal efficiency and concurrently mitigate knock, however, there is a lack of comprehensive work involving charge motions. In this paper, numerical simulation is employed to investigate the impact of charge motion on knock and thermal efficiency under high load conditions for a heavy-duty spark-ignition natural gas engine. The findings indicate that in the configuration with intense swirl, the diminished turbulent kinetic energy (TKE) at the combustion chamber’s base lessens the convective heat exchange between the fresh charge and the heated exhaust gases, resulting in a noticeable high-temperature zone and triggering hot spots. In configurations with inclined swirl and strong tumble motion, the extensive tumble motion near the spark plug region close to top dead center leads to an asymmetric flame front shape, determining the location of hotspots. The research also revealed that excessive tumbling motion and TKE can increase the likelihood of engine knock, while appropriate cylinder charge motion can improve the knock resistance of the engine to some extent, the maximum reduction in knocking intensity can reach 92.5%. The optimized combustion systems can significantly improve the initial combustion rate, shorten the ignition delay period, and advance the combustion center. With the combined effects of ignition timing and charge motion, the total indicated specific power per unit of fuel mass is increased in the optimized systems. Compared to the original combustion system, the indicated thermal efficiency within the knocking boundary can be improved by 1.11%.

Using blended Fuel of Ethanol and Petrol Analyze Performance of a Multi - Cylinder Spark Ignition Engine

Using blended Fuel of Ethanol and Petrol Analyze Performance of a Multi - Cylinder Spark Ignition Engine

Fuel consumption and exhaust emissions from Euro 6d vehicles fueled by innovative LPG/DME blend

The aim of this research was to investigate the exhaust emissions from vehicles when fueled by a new and fully renewable fuel if made of bio-LPG and renewable dimethyl ether (DME), in comparison with standard gasoline. For this purpose, DME was mixed with liquefied petroleum gas (LPG) and used to fuel three bi-fuel LPG/gasoline spark-ignition engines light-duty vehicles. The suitable fuel blend was selected based on several octane tests using CFR engines. Exhaust emissions were tested over the WLTC and over the hot-start CADC cycles, as well as on the road. All Euro 6 standards were well fully met over the WLTC with both fuels. Switching from gasoline to LPG/DME fueling, the CO and NOx emission factors increased for two vehicles, whereas THC and NMHC decreased. Regarding particulates, for two vehicles the emission factors decreased, too. Generally, when the vehicles were driven on the CADC, lower gaseous emissions were observed compared to WLTC: excluding one vehicle, when switching from gasoline to LPG/DME fueling, the overall emission profiles reflected those of the same vehicles run on the WLTC. The unregulated particulate emissions measured over both testing cycles reflect what was detected for the regulated ones. Except for PN10, which was not measured, all regulated emissions were found to meet the (most severe) Euro 7 standards proposed at first by the European Commission. RDE tests showed that all vehicle emissions obtained from on-road tests were also found to meet the RDE standards, regardless of the fueling. Concerning CO2 emissions, LPG/DME fueling guaranteed a systematic decrease for all vehicles and cycles, both on road and in the laboratory. The present investigation aims at demonstrating that the innovative LPG/DME 80 %/20 % (m/m) blend not only can be deemed as potentially suitable for GHG emissions reduction, as long as both DME and propane are obtained from renewable sources, but even compliant with EN 589 and both Euro 6 and part of preliminary Euro 7 exhaust emission proposal.

Effects of industrial hydrogen-rich gases on the performance of the spark ignition engine under various combustion modes

Hydrogen is emerging as a promising alternative to traditional fossil fuels for the transportation. Additionally, the hydrogen-rich gases (HRG) can produce on a large scale during the process of chemical production. In this study, the influences of HRG on the performance behaviors of the spark ignition (SI) engine are comprehensively analyzed under various combustion modes and operating conditions. The experimental results indicate that with increasing the lambda, the torque of the test engine can maintain the target value under equivalent ratio and lean combustion modes, while it sharply decreases under ultra-lean combustion. When the value of the lambda is 1.5, the brake thermal efficiency (BTE) and brake specific hydrogen consumption (BSHC) of the HRG SI engine respectively reach up to 33.6% and 89.1 g/kW.h, yielding superior fuel economy. The NOx emissions of the HRG SI engine firstly increase and then decrease with increasing lambda, reaching the peak value at the lambda of 1.1. In addition, the NOx, CO, and HC emissions of the HRG SI engine greatly reduce when the lambda is approximately 1.5. Consequently, using HRG partially substitute the traditional fossil gasoline in the SI engine can benefit to achieve energy conservation and emissions reduction in transportation section.

Correlation relationships of processes in the combustion engine in the RDE test

The article presents considerations on the processes taking place in the combustion engine in the in real driving operating conditions of a vehicle performing the RDE (Real Driving Emissions) test. The tests were carried out using a passenger car with a spark-ignition engine. The processes considered in the article were related to the engine operating states, exhaust emissions and fuel consumption, and the vehicle speed, which determines the engine operating conditions. The RDE test were carried out using PEMS (Portable Emissions Measurement System) equipment, and the following variables were recorded: vehicle speed, control, rotational speed, relative torque and relative engine power, emission pollutant intensity of: carbon monoxide, hydrocarbons, nitrogen oxides and carbon dioxide, the intensity of particle number and the fuel consumption intensity. The recorded signals were digitally processed, and the statistical properties of the variables and the mutual relation between the engine operating states were examined. The properties of the measured variables were investigated in the entire RDE test and in its constituent phases: the first, corresponding to vehicle movement in cities, the second – outside cities, and the third – on highways and expressways. The pollutant specific distance emission and the particle number specific distance as well as the specific distance fuel consumption were determined in relation to the average vehicle speed, and based on these results, the exhaust emissions and fuel consumption characteristics were created. Correlational studies of the considered variables were also performed. Pearson's linear correlation coefficients for the measured variables combinations were determined.

Experimental study on effect of use of oxyhydrogen blends with traditional fuels in spark engines for better performance

The utilization of oxyhydrogen as a supplementary fuel in internal combustion engines has garnered significant attention due to its potential to enhance engine performance and reduce emissions. This study investigates the effects of oxyhydrogen addition on the performance, emissions, and thermodynamic efficiencies of a spark-ignition engine fueled by gasoline, propane, and methane. The engine drives a commercial stationary power generator. The results demonstrate that oxyhydrogen addition leads to a consistent reduction in CO2 and hydrocarbon emissions across all fuel types, with the most substantial reduction observed in gasoline, decreasing from 2413 g/kg to 1709 g/kg (a 29 % reduction) with 20 % oxyhydrogen addition. However, NOx emissions tend to increase, particularly pronounced in gasoline, where they escalate from 9.5 g/kg fuel with no oxyhydrogen to 24.6 g/kg fuel for the same case (a 159 % increase). The power output exhibits varying degrees of improvement depending on the fuel type and oxyhydrogen concentration. Oxyhydrogen has compensated for the power reduction when propane and methane are used as the base fuel. The energy and exergy efficiencies consistently improve with increasing oxyhydrogen addition, with the most significant improvement observed in propane, where the energy efficiency increases from 30.0 % to 37.3 % with and addition of 20 % oxyhydrogen.

Evaluation of the Possible Effects of Varying the Volumetric Ratio of Lpg on the Spark Ignition Engine's Performance, Emissions, and Combustion

This study investigated the performance, emission reactions, and combustion of liquefied petroleum gas (LPG) at various volumetric ratios with gasoline. The experiments were carried out on a single cylinder spark ignition (SI) engine at different engine loads (500 to 3000 W). In general, the use of LPG has a negative effect on performance and combustion, while making a positive contribution to emissions. The brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) values closest to 100% gasoline were obtained with 25% LPG and were lower by 0.36% and 4.55%, respectively. Conversely, using LPG resulted in lower emissions of carbon dioxide (CO2), hydrocarbons (HC), and carbon monoxide (CO). The lowest emissions were obtained with the use of 100% LPG as 0.5%, 65 ppm and 9.5%, respectively. Compared to 100% gasoline, 20.63%, 27.78% and 5.19% improvements were achieved. Finally, the cylinder gas pressure value was negatively affected using LPG. Compared to 100% gasoline, the gas pressure value obtained with 75% LPG content fuel was 7.81% lower. It has been concluded that LPG is an environmentally friendly alternative fuel in terms of emissions, and considering the decrease in performance values, 25% LPG can be used successfully in SI engines instead of 100% LPG.

Comparative analysis of spark ignition engine performance using RON 95 and RON 100 gasoline fuels

Most of the vehicles used by Malaysians have engines that only require petrol RON 95 to power the engine. However, many people claimed that utilising RON 100 instead of RON 95 for their vehicles will improve engine performance. Furthermore, many people speculate that using oil with a low octane level in an engine with low performance will affect the engine's performance. The goal of this research is to analyse and compare the engine performance and emissions on a spark ignition engine using gasoline RON 95 and RON 100. In this study, a single-cylinder four-stroke engine running with RON 95 and RON 100 has been tested on an engine dynamometer to evaluate the brake power, torque, specific fuel consumption, and exhaust emissions. The emissions from the engines have been determined using a gas emissions analyser. The outcomes of the experiment have been analysed based on engine torque, braking power, and exhaust emissions. Based on the analysis, torque, brake power, and emissions data obtained from the dynamometer engine, RON 100 has a higher and smoother performance than RON 95.

Detection of Nickel Atoms Released from Electrodes in Spark Discharges Using Laser-Induced Fluorescence.

The reduction of greenhouse gas emissions and the effort of carbon neutrality require the improvement of spark-ignition engines in terms of efficiency and capability to operate on renewable fuels. The electrode wear of spark plugs, used for ignition of novel fuels and lean mixtures, emerges as a significant challenge in this transition. Understanding the physical mechanism and influence of spark operation parameters of the wear process is thus important. Compared to the conventional methodology of performing long-term wear tests, laser-based optical diagnostics methods are capable of assessing electrode wear during one single or a few spark discharges. In this work, the necessary initial steps required for performing optical investigations using laser-induced fluorescence (LIF) are presented. Several excitation pathways of nickel atoms were investigated, and 336.96 nm was identified as the optimal one. This excitation approach yielded emissions between 338.75 and 353.58 nm, effectively avoiding the major interference from N2 plasma emission in spark discharges. Additionally, a linear relationship in fluorescence signal intensity with excitation energy up to 400 µJ was observed. These findings indicate the potential of LIF for in situ diagnostics of electrode wear, contributing to engine development in both efficiency and compatibility with sustainable fuels.

Engine Performance and Emission Evaluation of Gasoline-Ethanol Fuel Blend in SI Engines Under Various Conditions of Load and Speed

Ethanol fuel is considered a renewable energy source with a lower global warming potential than gasoline. The purpose of this paper is to analyze the emissions and performance of gasoline-ethanol blends in SI engines under various conditions. A computerized 4s, 1cyl, VCR spark ignition engine is used for the tests to measure the performance of Gasoline-Ethanol (GE) blends in particular E-10 (10% ethanol, 90% gasoline). For measuring exhaust emissions as well as performance, regular gasoline fuel is used for the additional tests. Engine performance using ethanol-gasoline blended fuel has been evaluated at different working conditions: 1200–1800 rpm, AFR 0.9, STs 300, CR10:1. When vehicles running on ethanol-gasoline blend indicated a decrease in the amounts of HC, NOx, and CO exhaust gases while 3.9% increase in CO2 emissions as compared to unleaded gasoline fuel. Furthermore, it has been shown that the brake power, torque, specific fuel consumption increases when a Gasoline-Ethanol (GE) blend is used over regular gasoline fuel.

Empirical study on butanol-ethanol-gasoline blends using Artocarpus heterophyllus peel resource for eco-friendly gasoline engine application

Since using current engine fuels contributes to climate change and global warming, there is intense competition to provide an ecologically friendly and less harmful substitute fuel. It proved to be rather feasible to mix engine-designed fuel with alcohol fuel. In this work, the peel of Artocarpus heterophyllus is used to produce the bioethanol. In three ratios—10 % butanol-ethanol + 90 % petrol (BEG10), 20 % butanol-ethanol + 80 % petrol (BEG20), and 30 % butanol-ethanol + 70 % petrol (BEG30)-butanol-ethanol and petrol were mixed in the present work. Using a four-stroke, spark ignition (SI) engine one-cylinder, the effect of the butanol-ethanol-gasoline combination on operational properties was examined and studied. Three test fuels (BEG10, BEG20, and BEG30) were studied in the engine speed range of 2500 rpm to 4500 rpm. The best practical responses found were brake thermal efficiency (43.21 %) and brake-specific fuel consumption (0.23 kg/kWh). The findings showed that more significant concentrations of ethanol-butanol improve the performance characteristics. In the end, engine emission parameters such as hydrocarbon (40 %), carbon monoxide (25 %), and nitrogen oxide (5.88 %) were reduced by the butanol-ethanol combination with petrol. Artificial neural network (ANN) models of multiple regression are used to forecast the engine performance parameters. An ANN model is trained using a database produced from the experimental findings. It shows that the suggested artificial neural network model can provide a precise correlation between input variables and output replies. The input parameters like Speed, Load, and Blend were predicted using the identified model. The R2 (0.9638, 0.9735) value of BTE and BSFC obtained indicated that the neural network approach model generated was more accurate for the prediction process. ANN application is thus a superior forecasting tool for SI engine performance characteristics.

Effect of ignition timing on combustion characteristics and emissions of an X-type rotary engine with the high efficiency hybrid cycle

X-type rotary engines (XREs), using the high efficiency hybrid cycle, possess advantages of simple structure, high power-to-weight ratio, and high theoretical efficiency, making XREs as potential power sources in hybrid vehicles and small unmanned aerial vehicles. Typically, ignition timing has a promising potential to improve the combustion performance of spark ignition engines. In this work, the effects of ignition timing on flame propagation, combustion characteristics, and pollutants formation were studied adopting a three-dimensional simulation method. The results showed that at different engine speeds, significantly different flow forms and flow velocities in the larger chamber recess of the XRE were formed, resulting in large differences in flame propagation velocities at leading side and trailing side of the combustion chamber. Advancing ignition timing increased the flame propagation velocity at the given engine speed. Ignition timing had a more significant effect on peak pressure at medium-high speeds compared to low engine speeds. At 3000 RPM and 5000 RPM, the peak pressure was increased significantly with advancing ignition timing, but when ignition timing was advanced to -30 °CA, the increment in the in-housing pressure was minimal. As ignition timing was retarded, the ignition delay was slowly reduced. The effect of ignition timing on ignition delay was more significant for low speeds than for medium-high speeds. However, the influence of ignition timing on combustion duration showed the opposite trend. Delayed ignition showed a slight increase in indicated thermal efficiency and indicated mean effective pressure at low speeds, while the opposite was true at medium-high speeds. Nevertheless, the effect of ignition timing and engine speed on indicated specific fuel consumption is opposite to the trend of the above laws. With the increase of ignition timing, the NOx mass fraction first increased and then decreased at low speeds, with the maximum occurred at -30 °CA, but the NOx mass fraction continued to increase at high speeds. Soot and CO productions were slightly affected by ignition timing. To sum up, this XRE, setting the ignition timing of -30 °CA, achieved better flame propagation and engine performance at the price of a smaller increment of NOx emissions.

Numerical Analysis of the Effect of Ethanol-Gasoline Blends on a Single-Cylinder Spark-Ignition Engine Performance and Emissions

— With the rapid increase in the number of vehicles fueled by gasoline plying on the roads, there has been a rising need in the search for alternative fuels, which are more environmental friendly in order to reduce the amount of vehicular exhaust emissions. This can be achieved by using blended mixtures of gasoline with alcoholic fuels among which, ethanol is found to be most suitable due to its easy availability, low costs, safety and low impact on the engine performance. This study aims to investigate the performance of a single-cylinder, four-stroke spark-ignition engine using different ethanol-gasoline blends, namely E0, E10, E20 and E30. The engine's torque, brake power, brake thermal efficiency, brake-specific fuel consumption, and exhaust emissions were analysed using numerical simulation. Results revealed that raising the proportion of ethanol in the fuel mixture resulted in reduced brake power and torque upto 16% as a result of decrease in calorific value of the mixture. The engine's brake thermal efficiency decreased by upto 3% while the brake-specific fuel consumption increased upto 12% with increase in ethanol concentration. Exhaust emissions, including NOx and HC, were found to be influenced by engine speed, with NOx emissions increasing and HC emissions decreasing as speed increased. The study also revealed that increasing ethanol concentration in the fuel resulted in reduced engine exhaust emissions by upto 47% and 10% for NOX and HC emissions respectively. The study concluded that among all the blends used, optimum performance was obtained for E30 blend with reduction in exhaust emissions but at the expense of slight reduction in engine performance.

CFD Simulation of Pre-Chamber Spark-Ignition Engines—A Perspective Review

The growing demand to reduce emissions of pollutants and CO2 from internal combustion engines has led to a critical need for the development of ultra-lean burn engines that can maintain combustion stability while mitigating the risk of knock. One of the most effective techniques is the pre-chamber spark-ignition (PCSI) system, where the primary combustion within the cylinder is initiated by high-energy reactive gas jets generated by pilot combustion in the pre-chamber. Due to the complex physical and chemical processes involved in PCSI systems, performing 3D CFD simulations is crucial for in-depth analysis and achieving optimal design parameters. Moreover, combining a detailed CFDs model with a calibrated 0D/1D model is expected to provide a wealth of new insights that are difficult to gather through experimental methods alone, making it an indispensable tool for improving the understanding and optimization of these advanced engine systems. In this context, numerous previous studies have utilized CFD models to optimize key design parameters, including the geometric configuration of the pre-chamber, and to study combustion characteristics under various operating conditions in PCSI engines. Recent studies indicate that several advanced models designed for conventional spark-ignition (SI) engines may not accurately predict performance under the demanding conditions of Turbulent Jet Ignition (TJI) systems, particularly when operating in lean mixtures and environments with strong turbulence–chemistry interactions. This review highlights the pivotal role of Computational Fluid Dynamics (CFDs) in optimizing the design of pre-chamber spark-ignition (PCSI) engines. It explores key case studies and examines both the advantages and challenges of utilizing CFDs, not only as a predictive tool but also as a critical component in the design process for improving PCSI engine performance.

Influence of variable enhanced LIVC miller cycle coupled with high compression ratio on the performance and combustion of a supercharged spark ignition engine

A novel variable enhanced late intake valve closing (LIVC) Miller cycle with asynchronous valve opening was proposed. Relevant tests were carried out in a supercharged spark ignition (SI) engine with high compression ratio, which mainly included the effects of variable valve timing on performance and combustion characteristics, as well as the comparison with the baseline engine. The purpose of this study was to explore the effect of different intake and exhaust opening timing on the performance and combustion characteristics of the enhanced LIVC Miller cycle with asynchronous valve opening, and further explore the energy saving potential of this Miller cycle. The results showed that the application of variable enhanced Miller cycle effectively improved the anti-knock ability and pumping loss of the engine with high compression ratio. On the one hand, the optimization of pumping loss substantially improved the fuel economy under small load conditions. On the other hand, better combustion performance and air-fuel ratio could be achieved at medium and high loads. Meanwhile, the exhaust valve should be opened as earlier as possible to achieve the best fuel economy. Correspondingly, under optimal valve timing, compared with the baseline engine, the asynchronous intake valve opening variable enhanced Miller cycle engine with high compression ratio had a fuel economy optimization of more than 3.5 % under all loads, and the maximum fuel economy optimization was 12.74 % under the condition of 11 bar.

Optical Investigation of Sparks to Improve Ignition Simulation Models in Spark-Ignition Engines

The use of renewable fuels in place of fossil fuels in internal combustion engines is regarded as a viable method for achieving zero-impact-emission powertrains. However, to achieve the best performance with these fuels, these engines require further optimization, which is achieved through new combustion strategies and the use of advanced ignition systems such as prechambers. Since simulations greatly accelerate this development, accurate simulation models are needed to accurately predict the combustion phenomenon, which requires a deep understanding of the ignition phenomenon as it significantly affects combustion. This work presents a comprehensive experimental methodology to study sparks under engine conditions, providing quantitative data to improve and validate ignition simulation models. The goal was to determine the volume generated by sparks under engine conditions that can initiate combustion and use this information to improve simulation results to match the experimental results. The visible sparks were observed with high-speed cameras to understand their time-resolved evolution and interaction with the flow. The heat transfer from the plasma was also visualized using a modified Background-Oriented Schlieren technique. The information gained from the experimental observations was used to improve an ignition simulation model. Since the velocity of the plasma was found to be slower than the surrounding flow, a user-defined parameter was included to calibrate the velocity of the simulated plasma particles. This parameter was calibrated to match the simulated spark length to the experimental spark length. In addition, since the previous simulation model did not take the heat transfer from the plasma into account, the simulated plasma particles were coupled to have heat transfer to the surroundings. Based on a comparison of the simulation results with the experimental results, the improved approach was found to provide a better physical representation of the spark ignition phenomenon.

A consistent model of the initiation, early expansion, and possible extinction of a spark-ignited flame kernel

Modelling the establishment and growth of spark-ignited (SI) flame kernels has always been a topic of great interest, especially due to their key role in affecting the performance of SI engines. A major issue is that the unsteady conditions and the small kernel size hinder the application of the typical (both linear and non-linear) flame stretch correlations, valid only long after the ignition stage. Overcoming such limitations, this work presents a novel, mathematically consistent, and compact model that enables prediction of flame kernel initiation and early expansion, including its possible extinction. Firstly, spark-driven initiation models from literature are discussed, and an effective flame kernel initiation method is proposed. Then, the expansion model is defined complementing the mass, energy, and species conservation equations for the spherical kernel with the reactant and temperature profiles outside of it using the theory of transient thermodiffusive flames. After accounting for the convective flow caused by the combustion-induced density reduction and the variable thermodynamic properties of the reacting fuel/air mixture, the result is a two-equation model that predicts the kernel expansion even up to its possible extinction due to flame stretch. After calibration of the expansion model, successful validation is achieved against literature data on lean propane/air flames, and the influence of the model parameters is examined in detail. The proposed expansion model is formulated also aiming for inclusion into the simulation of combustion in SI engines, enabling more accurate predictions at part loads, as well as more effective estimation of the cycle-to-cycle variation thanks to the good model sensitivity to the parameters most affecting the ignition.

Effects of Various Bore–Stroke Ratios on Hydrogen Direct Injection Spark Ignition Engines With Variable Valve Timing Under Low-Load Conditions

Effects of Various Bore–Stroke Ratios on Hydrogen Direct Injection Spark Ignition Engines With Variable Valve Timing Under Low-Load Conditions

Effect of Fuel Injection Parameters on Engine Performance in A Conventional Single Cylinder Spark Ignition Engine

In this study, a 1D model was created using the Ricardo-Wave program for a single-cylinder, spark ignition, four-stroke, direct injection engine with a stroke volume of 398 cc. Air-fuel ratio (AFR), mixture temperature (MT), and start of injection (SOI) were used as fuel injection parameters. Using these parameters, 343 different cases were created. Brake power, thermal efficiency, and fuel consumption were used as engine performance parameters. By holding one injection parameter constant, a contour plot was created to examine the effect of the other two parameters on the engine performance parameter. According to the results, the effect of MT and SOI on brake power is 1%, the effect of AFR on brake power is 9.6%, the effect of MT and SOI on thermal efficiency is 1%, and the effect of AFR on thermal efficiency is 12.8%. The effect of MT and SOI on fuel consumption is 0.04%, the effect of AFR on fuel consumption is 22.9%, and the effect of AFR on brake specific fuel consumption is 22.9%. These results indicate that the most significant effect is provided by AFR, while MT and SOI also have a slight impact on engine performance.

RESEARCH OF THE COMBUSTION PARAMETERS OF GASOLINE WITH ADDITIONAL HYDROGEN IN A SPARK-IGNITION ENGINE IN EXTERNAL SPEED CHARACTERISTIC MODES

The directions of development and improvement of road transport around the world are inextricably linked to the desire to reduce the use of cars “on traditional fuels” due to limited oil and environmental safety of mankind. Since the modes of external speed characteristic are the most typical for the operation of cars in cities, the study of environmental performance of engines in these modes is an urgent task. Therefore, finding ways to reduce carbon dioxide emissions from automobile engines at high-speed modes is an urgent task. The rapid growth in the number of cars with internal combustion engines and the inevitable decline in world oil reserves necessitate the development and implementation of energy-saving technologies and the use of alternative fuels. Research aimed at finding ways to improve the fuel efficiency and environmental performance of automotive engines is relevant. One of the promising areas is the influence on the combustion process in gasoline engines by using additives of alternative fuels, which include hydrogen. The presented study of the parameters of combustion of gasoline with hydrogen additive in a spark ignition engine at external speed characteristics is a comprehensive analysis of the combustion process of a gasoline-hydrogen mixture and determination of its effect on the concentration of carbon dioxide in exhaust gases by developing a mathematical model that takes into account the composition of the mixture components and features of the combustion process, allows for sufficiently accurate calculation of the operating process of an engine with hydrogen additive at ψ ≤ 10%, its identification by the results of experiments. In the course of the study, dependencies were developed to determine the combustion parameters of the Wiebe model, taking into account the addition of hydrogen to gasoline in the modes of external speed characteristics, and the effect of hydrogen addition on the concentration of CO2 in exhaust gases was analyzed. It is shown that with an increase in the hydrogen additive to 10% by mass fraction to gasoline, there is a decrease in CO2 emissions to almost 30% in the external speed characteristic modes, which corresponds to modern environmental standards for gasoline internal combustion engines.