Browse Topic: Low emission vehicles (LEV) and zero emission vehicles (ZEV)

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A Modeling and Experimental Study of the Argon Power Cycle Using Mixing-Controlled Combustion2026-01-50436/19/2026
The closed-cycle hydrogen-fueled argon power cycle is a zero emissions concept that combines a carbon-free fuel with argon as a diluent replacement for nitrogen. The lack of nitrogen in the argon power cycle results in zero NOx emissions on an internal combustion engine platform. There is also massive efficiency improvement because argon is monatomic and has a very high ratio of specific heats. However, this will also result in combustion temperatures and pressures exceeding those normally achieved on an air-standard engine platform. The literature shows conflict between modeling, which promises incredibly high efficiency gains, and experiment, which show more modest efficiency gains. This work combined thermodynamic modeling, literature analysis, and experiments to understand this discrepancy and ultimately understand what level of efficiency gain can be expected for the argon power cycle. It was found that while low compression ratio engines stand to see the largest relative efficiency improvement, high compression ratio engines are the ones that can ultimately achieve ~60%+ efficiency, corresponding to a 15–20% relative improvement in efficiency over an air-standard engine platform operating at or above 50% efficiency. The elevated temperatures and pressures of the cycle result in knock in spark ignition, so either a high compression ratio knock mitigation strategy or mixing-controlled operation is required. Experiments conducted using a diesel-fueled compression ignition engine showed that a 30% argon replacement resulted in ~6% and full nitrogen replacement with argon resulted in ~14% relative efficiency improvement at 8 bar gross indicated mean effective pressure (IMEPg) without intake boosting on a heavy-duty engine with a compression ratio of 20.0 and late intake valve closing, agreeing with modeling results. The key takeaway to match modeling and experimental trends is to accurately model heat transfer, which increases significantly for the argon power cycle.
Gainey, Brian, Ahrling, Christoffer, Tunestal, Per, Tuner, Martin
Comparative Toxicological Assessment of Exhaust Emissions from Modern Low-Emission Passenger Vehicles2026-37-00056/9/2026
As vehicle technologies evolve toward electrification and advanced aftertreatment, understanding the biological implications of their exhaust emissions remains essential. This study presents a harmonized comparative toxicological assessment of five Euro 6 vehicles representing gasoline, hybrid, plug-in hybrid, compressed natural gas (CNG), and diesel technologies. Vehicles were tested under realistic driving conditions on a chassis dynamometer. Diluted exhaust was delivered directly to human lung epithelial cells (A549) using a controlled air–liquid interface (ALI) exposure system. Solid and total particle number emissions were measured, and deposited particle mass was estimated from size-resolved distributions and deposition efficiency. Vehicles equipped with particulate filtration showed lower solid particle emissions overall, while differences between gasoline particulate filter-equipped vehicles indicated that hybridization can further influence emission levels. Diesel operation during active diesel particulate filter (DPF) regeneration produced more than two orders of magnitude higher particle number emissions compared to normal operation. When expressed as deposited mass, vehicle ranking differed from number-based emissions, highlighting that emission metrics do not directly translate into delivered biological dose. Exposure to whole exhaust consistently induced stronger cytotoxic and inflammatory responses than to gaseous phase alone. Membrane integrity disruption and IL-1β release showed clear particle-associated amplification, with the strongest effects observed during diesel DPF regeneration. These findings demonstrate persistent technology-dependent differences in particle emissions and acute biological responses among modern low-emission vehicles.
Tsakonas, Georgios, Stamatiou, Rodopi, Lazou, Antigone, Samaras, Zissis, Elihn, Karine
The Impact of Zero-Carbon Fuels on CO 2 Emissions Reduction from the Long-Haul Heavy-Duty Truck Fleet in Mainland China13-07-01-00035/22/2026
The decarbonization of heavy-duty trucks (HDTs) is a crucial path for China to achieve its “dual-carbon” goals and transition to decarbonized freight transport. Zero-carbon fuels are key alternatives to fossil fuels for these high-emission vehicles. This study develops an integrated scenario analysis framework to quantify the theoretical CO₂e emission trajectories of China’s long-haul HDT fleet from 2020 to 2060. Functioning as a macro-level stress test, the model derives theoretical equivalent stock from anticipated logistics turnover demand, integrating them with well-to-wheel (WTW) emission factors under six distinct policy stringencies (Projects 1 through 6), representing varying paces of fossil fuel vehicle phase-out. The results demonstrate that policy stringency primarily governs the timing and depth of emission reductions, while fuel technology defines the minimum achievable emission level. Three-dimensional visualization analysis reveals a nonlinear “emission cliff” under aggressive policies, marked by accelerated HDT fleet renewal and exponentially growing mitigation benefits. This cliff is more pronounced for the green hydrogen pathway and demonstrates its superior potential for deep decarbonization. In Project 1, CO₂e emissions reach a mid-term peak in 2035. Compared to the diesel baseline, the green hydrogen and green ammonia transition pathways reduce peak CO₂e emissions by 158 and 137 million tons, corresponding to reductions of 10.0% and 8.6%, respectively, under the modeled theoretical boundaries. In contrast, the aggressive Project 6 policy suppresses this peak, triggers the “cliff” effect much earlier, and achieves an extremely low stabilization level by 2040—15 years ahead of Project 1. This study provides a macro-theoretical quantitative decision-support tool for policymakers. It demonstrates that transparent and aggressive phase-out policies are essential to accelerate fleet turnover, trigger the “emission cliff,” and firmly cap total cumulative emissions.
Wu, Yunmei, Huang, Hua, Li, Rui, He, Guijia, Liu, Bo, Liu, Ruowei, Xie, Yongliang
Development of a Zeolite-Based (HC/NOx Trap Type) Cold-Start Catalyst (CSC) for Meeting Tier4/LEV IV Tailpipe Emission Standards, Part IV2026-01-03644/7/2026
This paper is a follow-up study to three preceding reports [1,2,3] that focus on the development of a β-zeolite-based hydrocarbon/nitrogen oxide (HC/NOₓ) trap-type cold-start catalyst (CSC) — a cost-efficient technical strategy for meeting the increasingly stringent vehicle tailpipe emission standards for automotive exhaust systems, including Tier 4 and LEV IV, which are to be enforced in the near future. A core challenge in meeting Tier 4 and LEV IV exhaust emission standards lies in the fact that both the SC03 and US06 test cycles commence from ambient (cold) temperatures, as opposed to the elevated (hot) starting temperatures mandated for the preceding Tier 3 and LEV III standards. In the present study, a hybrid electric vehicle (HEV) fitted with two distinct Tier 3-certified exhaust aftertreatment systems—one officially certified to Bin 30 standards and the other a Bin 20-equivalent system (non-officially certified)—was subjected to testing under the cold SC03, cold US06, hot SC03, and hot US06 test cycles for the purpose of comparative analysis. To meet the Tier 4/LEV IV Bin 30 engineering target of 13.13 mg/mile for combined NOₓ+NMHC tailpipe emissions, the HEV with the Tier 3 Bin 30 system required an approximate 64% reduction in tailpipe emissions during cold SC03 tests, while the HEV with the Tier 3 Bin 20 system needed a 52% reduction. For cold US06 tests, these two HEVs required emission reductions of 50% and 38%, respectively, to achieve the same target. The higher tailpipe emissions observed in cold tests (relative to hot tests of the same cycles) are attributed to elevated cold-start emissions. The CSCs developed in this work were applied to modify the Tier 3 Bin 20 aftertreatment system, and vehicle tests were conducted with the CSC-modified systems under both cold SC03 and cold US06 cycles. Notably, the CSCs effectively reduced cold-start tailpipe emissions (NOₓ+NMHC) in both test cycles, enabling the HEV to meet the Tier 4/LEV IV Bin 30 engineering target of 13.13 mg/mile for NOₓ+NMHC tailpipe emissions. Detailed emission results, along with the effects of zeolite loading and Pd loading on CSC performance, were also investigated and are discussed in this manuscript.
Xu, Lifeng, Wei, Hong, Zhao, Pengfei, Ma, Ruibo, Wang, Lin, Qian, Wangmu, Qian, Menghan
Achieving 70% Urban Fuel Consumption Reduction: An Opposed-Piston Engine-Based Mild-Hybrid Powertrain Architecture for Light Commercial Vehicles (JLA-2/JLA-T)2026-01-04324/7/2026
This paper proposes a novel powertrain architecture for the urban Light Commercial Vehicle (LCV) segment, leveraging the compact JLA-2 opposed-piston (OP) engine paired with the reconfigurable JLA-T mild-hybrid architecture. Within SAE literature, OP engines are consistently associated with simplicity. As highlighted by Tom Ryan III (2008 SAE President) in the foreword of Opposed Piston Engines: Evolution, Use, and Future Applications, this architecture is characterized by its manufacturing simplicity” and described as a “relatively simple, robust, and cost effective” power unit solution. The present work builds on this established view. The JLA-2 engine solves traditional packaging constraints by reducing the block width by 30% for horizontal installation and is volumetrically self-sufficient, eliminating external compressors. Although the gear train required for crank synchronization introduces design challenges, explicitly accounted for in our model, the elimination of the cylinder head and valve train reduces component count. The study utilizes a comprehensive computational methodology—incorporating 0D/1D thermodynamics, 3D CFD, and FEA—to evaluate the system against a standard Ford Escape baseline. The JLA-T module mechanically blends torque using a planetary gear-set and a low-voltage 48V electric assist, capturing electrification benefits without the high costs and safety complexities of high-voltage systems. Simulation results suggest significant performance improvements, notably achieving a sub-9-second 0-100 km/h acceleration and enabling Zero Emission Vehicle (ZEV) compliance in restricted zones. Most significantly, the analysis indicates that this platform delivers up to a 70% reduction in urban fuel consumption when operated as a PHEV, driven by the system’s modularity and optimized energy recovery. This paper presents the system architecture, control logic, and performance comparisons, demonstrating a feasible technical pathway for decarbonizing urban transport fleets. (Note: “JLA” serves as the proprietary designation for the engine and electromechanical hybrid system series proposed by the authors).
Nigro, Norberto, Aguerre, Horacio, Carignano, Mauro Guido, Alonso, José Luis, Juni, Carlos A.
In-Use Life Digital Twin (Redundant Storage) and Swappable Use Case for Battery Durability2026-01-03974/7/2026
As regulatory frameworks for zero-emission vehicles (ZEVs) and battery electric vehicles (BEVs) continue to evolve, there is growing emphasis on monitoring battery durability and usage throughout the vehicle lifecycle. These regulations increasingly specify the use of data monitors and tracking mechanisms to assess battery health and performance. In addition, regulations require anti tampering mechanisms especially for monitors that have external write access. Historically, regulations focused primarily on vehicle warranty; however, with the introduction of battery durability monitors, clarity is needed for the new battery durability monitors. More specifically if the battery durability monitors track with the lifetime of the vehicle or if they follow the lifetime of the battery. Furthermore, current regulations provide no guidance on high-voltage (HV) traction battery service strategies or methods to protect monitors from tampering by external customers. This paper will classify battery durability tracking parameters (DIDs) according to whether they align to the lifetime of the vehicle or the battery itself. Building on this classification, a service strategy is proposed that considers typical vehicle architectures: when the battery management Electrical Computer Unit (ECU) is fully integrated with or separated from the high voltage traction (HV) battery. The outlined service strategy not only supports regulatory compliance, but also enhances data integrity by mitigating the risk of tampering with monitored parameters through a Digital Twin framework. More specifically, the Digital Twin framework introduces redundant storage of critical information in multiple storage locations such as ECUs and then a mechanism for correlating that critical information to determine a mismatch. This approach anticipates future requirements for tamper-proofing and ensures secure, reliable tracking of battery durability metrics through redundant ECU storage.
Laskowsky, Patricia, Bunnell, Justin, Zettel, Andrew, Albarran, Josue
BEV Incremental CO 2 Emissions in a Ranked Order Electric Grid2026-01-04244/7/2026
Battery Electric Vehicles (BEV) have been sold as ‘Zero Emissions Vehicles’ (ZEV) by governments to reduce transportation CO2. While they are not ZEV because they run on grid electricity, they could be ‘effectively ZEV’ if the incremental CO2 is ‘very small’. At the national level, this is estimated using following metrics: (1) Internal Combustion Engine Vehicle (ICEV) fuel consumption, from the total US gasoline consumption divided by the total fleet miles driven, 25 mpg or 350 g CO2/mi, (2) Strong Hybrid Electric Vehicles (HEV) about one third less, 240 g CO2/mi. (3) BEV energy consumption, using data from systematic on-road testing of a wide range of vehicles, estimated at 40 kWh/100 mi for a US sales mix. (4) Electricity marginal CO2: in a ranked order grid, zero-CO2 sources are prioritized and supplemented by fossil sources. IEA hourly data show that the US 48 contiguous states are self-contained, with zero-CO2 sources providing a third of total demand. The response to hourly demand changes comes largely from natural gas and coal power stations, with EPA data showing a combined marginal CO2 of 600 g CO2/kWh. On replacing an ICEV by a BEV, the reduction in gasoline use, - 350 g CO2/mi, is offset to two thirds by higher electricity consumption, 40 x 600 / 100 = + 240 g CO2/mi. BEV marginal CO2 is therefore similar to HEV, and not ‘much smaller’ than ICEV. This is because HEV engines and fossil power stations have similar efficiency and similar fuel CO2 intensity.
Phlips, Patrick
PRECISE FIT26AUTP04_024/1/2026
Why precision engineering is defining confidence in next-generation internal combustion engines. In 2026, the global transport industry, and particularly the automotive industry, finds itself under competing pressures. Regulators are tightening emissions standards, with new regulations such as the EU's Euro 7 being proposed to reduce air pollution in line with net-zero ambitions. Fleet operators are managing ever-aging vehicle populations in uncertain economic conditions, and policymakers are accelerating mandates for sustainable fuels, with countries like the UK moving forward with a Zero Emission Vehicle mandate by 2035. Across passenger vehicles, commercial transport, and off-highway machinery, engineers are now tasked with delivering measurable carbon reduction using a combination of electrification, advanced internal combustion engines (ICE) and fuel innovation without compromising safety, durability or performance.
Anderson, Todd
Optimizing Powertrain Performance a Customer Usage-Centric Approach2026-26-00671/16/2026
The US trucking industry heavily relies on the diesel powertrain, and the transition towards zero-emission vehicles, such as battery electric vehicles (BEV) and fuel cell electric vehicles (FCEV), is happening at a slow pace. This makes it difficult for truck manufacturers to meet the Phase 3 Greenhouse Gas standards, which mandate substantial emissions reductions across commercial vehicle classes beginning of 2027. This challenging situation compels manufacturers to further optimize the powertrain to meet stringent emissions requirements, which might not account for customer application specifics may not translate to a better total cost of ownership (TCO) for the customer. This study uses a simulation-based approach to connect customer applications and regulatory categories across various sectors. The goal is to develop a methodology that helps identify the overlap between optimizing for customer applications vs optimizing to meet regulations. To use a data-driven approach, a real-world customer usage pattern analysis was conducted to identify key performance metrics required to optimize driveline components. Additionally, the impact of certification requirements on vehicle performance is examined to ensure compliance while maximizing the benefits of the proposed optimization strategies. The findings of this research will provide valuable insights for manufacturers, enabling the development of trucks that are not only efficient and high-performing but also compliant with environmental standards, ultimately leading to a more sustainable future in the trucking industry.
Mohan, Vignesh, Darzi, Mahdi
Totem-Pole PFC and LLC Resonant Converter based 6.6kW On-Board Charger for LEV Applications2026-26-01601/16/2026
As light electric vehicles (LEVs) gain popularity, the development of efficient and compact on-board chargers (OBCs) has become a critical area of focus in power electronics. Conventional AC-DC topologies often face challenges, including high inrush currents during startup, which can stress components and affect system reliability. Furthermore, DC-DC converters often have a limited soft-switching range under light load conditions, leading to increased switching losses and reduced efficiency. This paper proposes a novel 6.6 kW on-board charger architecture comprising a bridgeless totem-pole power factor correction (PFC) stage and an isolated LLC resonant DC-DC converter. The main contribution lies in the specific focus on enhancing startup behavior and switching performance. In PFC converters, limiting inrush current during startup is crucial, especially with fast-switching wide-bandgap devices like SiC or GaN. Conventional soft-start techniques fall short in of ensuring smooth voltage transitions. Moreover, maintaining stable operation across a universal input voltage range and achieving a high-power factor under light load conditions remain persistent challenges. Although resonant converters are widely used for their natural soft-switching ability, achieving zero voltage switching (ZVS) over a wide range of loads, especially at light load conditions, is still a technical challenge. Existing solutions rely on complex control strategies or hardware modifications, which increase cost and design complexity. The proposed architecture was modeled and simulated using MATLAB/Simscape to assess dynamic and steady-state behavior under a range of operating conditions. Results demonstrated high input power factor, line/load regulation, and switch-node waveforms to confirm ZVS operation. Additionally, the proposed charger exhibits low harmonic distortion, ensuring compliance with IEC 61000-3-2 power quality standards. These findings confirm the topology’s effectiveness for high-performance LEV charging and set a strong foundation for future experimental validation and hardware development.
Patil, Amruta, Bagade, Aniket
Total Cost of Ownership Analysis of Fuel Cell and Hydrogen-Powered Commercial Vehicles for Cost Competitiveness with ICE and BEV2026-26-02541/16/2026
Worldwide, the automotive industry is pivoting towards electrification and zero-emission vehicles (ZEV) to address greenhouse gas emissions and to meet net-zero emission goals. Although pure electric vehicles with rechargeable high-voltage batteries seem to be the most popular choice to achieve climate goals, hydrogen-powered vehicles are also seen by many as a viable technology to clean up the transportation sector. Hydrogen fuel cells and fuel cell-powered vehicles have been in development for a long time, and hydrogen internal combustion engines (ICE) have seen rapid development in the past few years. While the technological feasibility of hydrogen fuel cells and H2 ICE is being proven, the mass adoption of these technologies depends, along with other factors such as hydrogen infrastructure, upon financial feasibility as well. This paper presents a systematic analysis of the total cost of ownership (TCO) of hydrogen-powered vehicles, especially fuel cell electric vehicles. Different commercial vehicle categories are analysed to assess the vehicle classes and use cases where hydrogen fuel cell-powered vehicles can be a cost-effective alternative to conventional ICE and battery electric vehicles (BEV). The analysis also determines the factors that contribute most to TCO, which will help identify the areas that require improvement/development or policy support to make fuel cells and hydrogen power more widespread. The paper also analyses the sensitivity of TCO to different cost factors, such as hydrogen cost, which helps in establishing cost targets to make hydrogen-powered vehicles a cost-effective solution in the transition to zero-emission transportation. Finally, different market trends are analysed to predict the timelines in which fuel cell-powered vehicles can become cost-competitive with ICE and BEV.
Jacob, Joe, Chougule, Abhijeet
Challenges for Truck Decarbonization: Load Distribution Evaluation According to Contran Resolution N° 882/20212025-36-019212/18/2025
The road transport mode is predominant in Brazil, representing more than 50% of greenhouse gas (GHG) emissions from energy sector [1]. Currently, trucks use internal compression combustion engine (ICCE) with fuel Diesel as propulsion, considering the reference for technical and economic studies for alternative propulsions such as: electrification or hydrogen (H2) as fuel. Both technologies are extremely important to achieve the goals defined by Brazilian nationally determined contribution (NDC) (commitment to Paris agreement target) to avoid climate changes catastrophic issues due climate temperature risk to exceed 2°C. In addition, several companies have announced sustainability compromises to contribute with reduction of GHG emissions in scopes 1,2 and 3, focusing on Environmental, Social and governance (ESG), where road transportation has a larger contribution to achieving the target. Contran Resolution (CR) n° 882/2021 defines the maximum weights and dimensions of vehicles to be authorized to circulate in Brazilian roads. A major challenge is the eligibility of the system to be installed, as well as the layout arrangement in the vehicle. In the context, during the concept phase, it is necessary to evaluate the load distribution on the axles, maximum weights and maximum dimensions of the vehicle complying with the legal requirements. Legal requirements modifying has been started in some countries, for example Chile where recently had public a resolution n° 181/2025 allowing to increase 350 kilograms (kg) in a single front axle, probably part of new policies to make feasible alternatives propulsions to reduce GHG emissions. The proposal of this work will evaluate the impact of load distribution through the assessment of possible layouts for purely electric propulsion or hydrogen fuel propulsion using software as tool, searching for greater agility in concept evaluation. The challenge is to create a model where it is possible to modify the gravity of center (CoG) along the vehicle considering curb weight, implementation, gross weight and payload, checking if it possible to follow the same premises of ICCE and current CR without miss customer by criteria. The results show the impact of reduced payload by 15-34% due to mass added in vehicle for zero emission vehicle (ZEV) using alternative propulsion (electric and hydrogen) in all scenarios simulated, considering the same dimensions of ICCE complying with CR. As conclusion, has been observe challenges for truck decarbonization due to payload reduction, generating direct impacts in customers due the possible total cost operation (TCO) increase. In additional this work can contribute to new decarbonization mobile polices discussion in the future (technical or compensation rules), where the tool used can contribute to build Fastly many different scenarios for decision. As recommendation, the CR updated n°1015/24 does not comply all decarbonization truck scenarios and will need be discussed how reduce the impact for ZEV concepts, resulting in CR updates to make the plan feasible for the truck decarbonization,
Ferreira, Bruno Francisco, Oliveira Da Silva, Laura de
Letter from the Guest Editors04-19-01-000112/10/2025
Letter from the Guest Editors
Assanis, Dimitris, Cho, Seokwon, Lawler, Benjamin, Pintor, Dario Lopez
Letter from the Guest Editors13-06-03-001711/12/2025
Letter from the Guest Editors
He, Xin, Belgiorno, Giacomo, Joshi, Ameya
Methodology for Underhood Air Prediction for Low Fidelity Computational Models2025-28-043110/30/2025
Thermal management is critical for modern vehicles, particularly for Zero Emission Vehicles (ZEVs), where maintaining optimal temperature ranges directly influences thermal system efficiency and vehicle range. Accurate prediction of underhood airflow behavior is essential for effective thermal management and also to estimate overall energy consumption by cooling system, with air-side dynamics playing a pivotal role in heat transfer over the heat exchangers of cooling package. Simulation tools like GT-Suite are indispensable for this purpose, enabling engineers to evaluate complex thermal interactions without the cost and time constraints of extensive physical testing. While 3D Computational Fluid Dynamics (CFD) models offer detailed insights into flow characteristics, they are computationally expensive and time consuming. In contrast, 1D models provide faster simulation times, making them ideal for system-level analysis and iterative design processes. However, 1D models inherently lack the ability to capture detailed flow phenomena, which can compromise the accuracy of thermal predictions. To mitigate this, calibration using 3D CFD data or experimental measurements becomes critical, ensuring that air-side behavior is represented as accurately as possible. One of the key challenges in this calibration process arises at low fan speeds, where matching flow rates becomes difficult due to the unavailability of windmilling data. Along with calibration of normal operating conditions, this paper also presents a methodology for tuning fan maps under such constraints, focusing on strategies to enhance model fidelity and novel methodology to calculate fan mechanical power. We explore simulation-based techniques, leveraging steady-state operating conditions to refine fan characteristics. The study further discusses sensitivity analysis, validation strategies, and potential inaccuracies introduced by missing windmilling effects and method to accurately fill in the missing fan map data. The proposed methodology ensures improved predictive accuracy of underhood airflow behavior, enhancing thermal system design for automotive applications. This method improves the reliability of underhood airflow predictions, ultimately contributing to more accurate thermal management system predictions out of digital tools.
Mutyala k, Akhil, Pudota, Praveen, Faseel, Ihsan, Gole, Pranali, Bashir, Murad
Evaluation of Alternative Cooling Method for High Performance Resistors in Zero-Emission Trucks2025-28-035910/30/2025
High Performance Resistors (HPR), also known as brake resistors are used in zero emission vehicles (ZEVs) to dissipate excess electrical energy produced during regenerative braking, as heat energy. It is necessary to use a suitable cooling technique to release this heat energy into the atmosphere in a regulated manner. Currently in most of the ZEVs, liquid cooled HPR with its dedicated heat exchanger and other auxiliaries such as pump, surge tank, Coolant and coolant lines, is used which increases the cost, packaging space and assembly time. This paper presents air cooling as a substitute heat-exchanging technique for high-performance resistors which eliminates the need of auxiliaries mentioned above, resulting in space optimization and reduction in assembly time. An air cooled HPR, designed for this study consists of a heat exchanger, which accommodates a resistor wire within its tubes. The design was made to fit commercial vehicle use, specific to trucks, due to packaging constraints in vehicle under hood. 1D simulation model made with MATLAB Simulink was used to analyse this design's heat rejection capabilities. The results conclude that for sufficient air flow rate, air cooled HPR can be used as an alternative in trucks.
Menariya, Pravin Ganesh, Kumar, Vishnu, Arhanth, Mahima, Umesha, Sathwik, Jagadish, Harshitha
Quantitative Analysis for Optimizing Thermal Management in Fuel Cell Vehicles2025-28-035810/30/2025
Zero emission vehicles are essential for achieving sustainable and clean transportation. Hybrid vehicles such as Fuel Cell Electric Vehicles (FCEVs) use multiple energy sources like batteries and fuel cell stacks to offer extended driving range without emitting greenhouse gases. Optimal performance and extended life of the important components like the high voltage battery and fuel-cell stack go a long way in achieving cost benefits as well as environmental safety. For this, energy management in FCEVs, particularly thermal management, is crucial for maintaining the temperature of these components within their specified range. The fuel cell stack generates a significant amount of waste heat, which needs to be dissipated to maintain optimal performance and prevent degradation, whereas the battery system needs to be operated within an optimal temperature range for its better performance and longevity. Overheating of batteries can lead to reduced efficiency and potential safety hazards, while low temperatures can decrease battery performance and range. The multiple temperature control loops in the thermal system design of the current FCEVs require significant energy for continuous heating and cooling. This is due to the fact that each of them exchanges energy directly with an external source or sink without redistributing energy among themselves. This can lead to energy losses during the heat exchange process. Our goal is to optimize thermal energy usage while maintaining the same performance and efficiency of both battery electric system and the fuel cell stack in a vehicle. In this paper, an analysis of thermal energy utilization of a single system is compared to the exchange of thermal energy across multiple systems, considering various heating and cooling scenarios. We compare our proposed strategy (with redistribution) with the existing strategy (without redistribution) quantitatively with respect to controller effort/ energy spent in achieving thermal target.
BHOWMICK, SAIKAT, Churi, Chetana
Optimization of CI Engine Operation with DME on an FTP Cycle2025-01-039410/7/2025
Fuels that can be produced in a sustainable manner are of high interest because they can provide an essential step toward net zero emissions vehicles. This study examines the combustion of one such fuel, Dimethyl Ether (DME), in a compression ignition, 4-cylinder, 2.2L engine. Testing was conducted using the Federal Test Procedure (FTP) certification cycle from the US Environmental Protection Agency (EPA). Different sets of calibration maps were designed to target low-NOx (30-50ppm) by using high EGR and intake throttle and high-NOx (approximately 1000ppm) using no EGR. An intermediate, mid-NOx calibration was also evaluated. Varying calibration approaches yielded total integrated engine out emissions ranging from 118 to 145gCO2/km, all below the 191gCO2/km from the baseline diesel. The corresponding NOx+UHC and CO emissions were also evaluated. The mid-NOx calibration was overall more favorable, as it met TIER 3-Bin 20 emissions requirements with the current efficiencies of the base engine diesel aftertreatment system. This paper reviews the transient behavior with three different calibrations, noting the effect of air-to-fuel ratios where the engine combustion efficiency deteriorates. It also highlights the impact of improved air and fuel controls, and the application of real time combustion feedback to enhance the combustion stability of the engine and the reduction of CO2 emissions. The paper explores the impact of renewable DME, and its carbon index, on the CO2 emissions for the low-NOx calibration. While a 5% renewable DME content can reduce the CO2 to the target level, the fuel consumption remains high due to the poor combustion efficiency and corresponding high HC and CO during transient operation.
De Ojeda, William, Wu, Simon (Haibao), Harrison, Christopher, Hall, Carrie, Arslan, Elaheh, Pulpeiro Gonzalez, Jorge
Data-Driven Modeling of H2-SCR Catalysts for Real-Time Estimation of NOx Reduction Efficiency2025-24-00849/7/2025
Achieving zero emissions across transportation is a tremendous challenge. The upcoming Euro 7/VII standards, set to be enforced in 2025, will mandate further reduction in ICEs exhaust emissions. Thus, additional improvements and potential new technologies and fuels are needed to design ultra-low emissions vehicles. Hydrogen seems to be a very attractive fuel, thanks to its high lower heating value, clean combustion, and extremely low pollutant emissions, due to the zero-carbon content. Nevertheless, NOx emissions are still an issue in hydrogen fueled engines and optimized lean-burn combustion and suitable after-treatment NOx reduction are mandatory to reach high specific power and efficiency and near zero NOx emissions, thus enabling H2-ICE powered vehicles to be zero-impact emitting technology solution. Selective Catalytic Reduction by using NH3 as the reducing agent is the most effective control technology for NOx abatement. Nevertheless, ongoing research and innovation are critical in developing new strategies for reducing NOx emissions, to overcome the NH3-SCR system main critical issues (extra equipment for urea storage and dosing, ammonia-slip, deactivation and fouling, low efficiency at low temperature). The SCR of NOx by hydrogen is considered a promising alternative to traditional ammonia-based deNOx technology. The H2-SCR catalysts are suitable for engine exhaust after-treatment during cold-start and urban-driving operations, exhibiting higher catalytic activity for low-temperature NOx emissions conversion (180 – 200 °C). Furthermore, in H2-ICE powered vehicles, the additional tank to store the reducing agent is not needed with a significant simplification of the engine exhaust lay-out. Experimental investigations on different H2-SCR catalysts have demonstrated that the conversion activity is greatly affected by the catalytic system configuration, the adsorption properties of the support material, the H2 spillover, that in turn are affected by H2/NO ratio and exhaust gas composition, temperature and flow rate. In the present paper, a feed-forward neural network model of H2-SCR is presented, with the aim of performing real-time estimation of reduction efficiency and supporting the design of suitable H2 management to achieve maximum NOx reduction and minimum hydrogen consumption. Model training and identification are carried out against a large set of experimental data measured on a H2-SCR small scale prototype at the Synthetic Gas Bench. The experimental tests were designed to reproduce the real conditions expected at the exhaust of a H2-fueled engine.
Crispi, Maria Rosaria, Conde Cortabitarte, Carla, Occhicone, Alessio, Piqueras, Pedro, Arsie, Ivan, Pianese, Cesare
Integrated CFD-Experimental Methodology for Hydrogen-Fuelled Small Loop Scavenged Two-Stroke Engines2025-24-00149/7/2025
This paper presents an integrated methodology for the analysis of hydrogen-fueled 2-Stroke engines, combining experimental data, 1D-CFD simulations, and 3D-CFD combustion calculations. The proposed approach aims to enhance the understanding of scavenging, injection, and combustion processes in a 50 cm3 loop-scavenged engine with low-pressure direct hydrogen injection, experimentally studied on a test bench. The hydrogen-fueled engine was capable of achieving a maximum power output of 3.1 kW, using a slightly lean air-to-fuel ratio (lambda = 1.3). The maximum engine speed for stable combustion without knocking was achieved at wide open throttle at 7119 RPM. The developed 1D-CFD model, based on the engine layout at the test bench, was calibrated using average experimental data and specific full load operating points. 3D-CFD simulations were performed for one full load operating point, focusing on combustion dynamics and fuel distribution within the chamber, with combustion model parameters calibrated to ensure consistency with experimental data. The integrated approach resulted in a good agreement between numerical results and experimental data. The proposed methodology enables accurate model calibration and a deeper understanding of complex physical phenomena, representing a valuable tool for the development of low emission engines.
Caprioli, Stefano, Ferretti, Luca, Scrignoli, Francesco, Fiaschi, Matteo, D'Elia, Matteo, Oswald, Roland, Schoegl, Oliver, Nambully, Suresh Kumar, Rothbauer, Rainer, Mattarelli, Enrico, Kirchberger, Roland, Rinaldini, Carlo
SAE TOMORROW TODAY - Powering A Cleaner Commercial Vehicle Industry135328/29/2025
From battery-electric trucks to hydrogen fuel cell vehicles, the company behind Kenworth, Peterbilt, and DAF is leading the charge toward zero-emissions. PACCAR is a global technology leader in the design, manufacture, and customer support of premium light-, medium- and heavy-duty trucks. The company is also actively investing in zero-emission technologies, positioning itself as a leader in the transition to cleaner commercial vehicles. To learn more, we sat down with Dr. Philip Stephenson, General Manager, PACCAR Technical Center and Executive Chair of this year's COMVEC, the annual commercial vehicle engineering conference hosted by SAE International. Listen in for an engaging discussion on PACCAR's approach to battery-electric trucks, hydrogen fuel cell vehicles, and charging infrastructure partnerships. And if you enjoyed this conversation, register now for COMVEC and join us as we bring together industry leaders, engineers, and innovators to discuss the latest advancements in on- and off-highway mobility technologies. We'd love to hear from you. Share your comments, questions and ideas for future topics and guests to podcast@sae.org. Don't forget to take a moment to follow SAE Tomorrow Today--a podcast where we discuss emerging technology and trends in mobility with the leaders, innovators and strategists making it all happen--and give us a review on your preferred podcasting platform. Follow SAE on LinkedIn, Instagram, Facebook, Twitter, and YouTube. Follow host Grayson Brulte on LinkedIn, Twitter, and Instagram.
Patterson, Lori
Optimized Cabin Heating Strategy for Battery Electric CEP Vehicles2025-01-02637/2/2025
Electromobility is gaining importance in the courier, express and parcel (CEP) sector, as parcel service providers increasingly rely on zero-emission vehicles to improve their CO₂ footprint. A common drawback of battery electric vehicles is their reduced range under cold operating conditions, due to the increased energy demand for cabin heating. Another CEP-specific factor influencing both energy consumption and cabin comfort is the frequent opening of doors during parcel delivery. Additionally, during delivery phases, the cabin cools down in the driver’s repeated absence from the cabin, as the heating is inactive. Nonetheless, a sufficient level of thermal comfort must be maintained during the driving phases between delivery stops. This paper presents an optimization-based strategy for the cabin heating of battery electric CEP vehicles. The objective is to maximize cabin comfort during driving phases while maintaining efficient energy consumption. For this purpose, a nonlinear model predictive control approach is developed. Characteristic CEP load cases are identified using a k-means clustering analysis of field data to assess the optimization approach. Assuming that the phases of parcel delivery can be accurately predicted, model-in-the-loop (MiL) simulations indicate significant potential for improving comfort. The optimization potential depends on the underlying CEP load cases, particularly the stop characteristics and the accepted energy consumption. For CEP load cases with low stop density, the simulation results indicate a 16 % reduction in energy consumption and a 21 % increase in comfort compared to the baseline heating strategy. The energy reduction and comfort improvement are achieved by optimizing the air mass flow rate and the heating power. In contrast, for load cases with high stop density, a significant improvement in cabin comfort can only be achieved with an increased energy consumption. In these load cases, a 30 % increase in energy consumption results in a 44 % improvement in comfort.
Rehm, Dominik, Krost, Jonathan, Meywerk, Martin, Czarnetzki, Walter
Overview of Indian Government Policies, Regulations and Automotive Company Strategies toward Net-zero Emissions2025-01-01846/16/2025
The automotive sector in India is undergoing a transformation, driven by government policies and regulations aimed at achieving net-zero carbon emissions. In alignment with global climate goals, the Indian government has set ambitious targets to reduce greenhouse gas emissions, with a focus on promoting Electric Vehicles (EVs) and Hydrogen Fuel Cell Vehicles (FCVs). Initiatives like the Faster Adoption and Manufacturing of Hybrid and Electric Vehicles (FAME) Scheme, along with tax incentives, subsidies, and charging infrastructure development, are designed to accelerate the adoption of cleaner vehicles. The introduction of stricter emission standards and the National Electric Mobility Mission Plan (NEMMP) further underscores the push toward sustainable mobility. In response, Indian automotive companies are shifting strategies to align with these government directives. Major players are significantly increasing investments in EV technology, focusing on enhancing battery performance, expanding manufacturing capacities, and improving charging networks. Meanwhile, hydrogen fuel cell technology is being explored as a potential solution for specific sectors like long-distance trucking and buses, with pilot projects underway to assess the feasibility of hydrogen infrastructure in India. The future market trends in India point toward rapid growth in both EVs and FCVs, driven by supportive government policies, evolving consumer preferences, and advancements in technology. As India moves toward its carbon-neutral goals, the automotive industry’s shift to zero-emission vehicles is pivotal. This paper explores the synergy between government regulations, automotive industry strategies, and market dynamics in shaping India’s transition to a sustainable transportation future.
Patil, Nikhil Nivrutti, Saurabh, Saurabh, Bhardwaj, Rohit, Gawhade, Ravikant, Gadve, Dhananjay, Amancharla, Naga Chaithanya
Vehicle Decarbonization: Vol. 3EPRCOMPV0720244/30/2025
Lin, Rui, Adas, Camilo Abduch
Green Hydrogen Production: Progress, Challenges and Proposed Solutions2025-01-86014/1/2025
Recently, global interest in hydrogen as a powerful, promising and clean source of energy has increased. Green hydrogen production (GHP) is considered one of the most important modern projects worldwide, as it is the way to achieve a clean, healthy and sustainable environment. GHP plays a major role to improve public health. There are several methods for producing or harvesting green hydrogen, the most famous of which are: 1) The electrolysis of water using a proton exchange membrane and metal foam at low temperatures and 2) Flash Joule Heating (FJH) method for heating plastic waste at high temperatures using low-carbon emissions technology. However, both methods still suffer from some difficulties. This calls for the need to search for scientific solutions to make hydrogen available at reasonable prices. While the first method is considered better for producing high-purity hydrogen compared to the second method, it faces challenges in collecting hydrogen on the surface of the negative electrode (cathode) in a suitable manner (catalyst) to collect it in a less expensive way. While the second method is considered the cheapest, but it is complex and requires very high temperatures to produce graphene with hydrogen harvesting. Graphene can be used in the manufacture of digital processors, electronic cells and conductors. Green hydrogen is used sparingly in some applications such as automotive research and some metallurgical and chemical industries. The paper focused on monitoring and understanding the current situation and challenges to provide proposed solutions for enhancing hydrogen production based on advanced engineering materials and metrology techniques. These solutions aim to develop the cathode material and its surface in the first method. Furthermore, the use of SEM and AFM in both methods was proposed to improve the characterization process of both the cathode material with its surface and GHP. Adopting such approach is essential to contribute for reducing the costs of GHP with the aim of providing clean and sustainable energy, in addition to enhancing the role of doctors in performing their medical duties towards raising the level of health awareness of community members and maximizing the treatment and recovery of patients in a healthy environment.
Hamed, Maryam Salah, Ali, Salah H. R.
Hydrogen Energy and Dongfeng Hydrogen Engine Development2025-01-71131/31/2025
Hydrogen energy is the best form of energy to achieve "carbon peak, carbon neutrality", and is known as the most promising clean energy in the 21st century because of its diverse sources, clean and low-carbon, flexible and efficient, and wide application sce-narios. Hydrogen internal combustion engine has the advantages of zero carbon emission, high efficiency, high reliability and low cost, and has become one of the important directions of hydrogen energy application. The paper first analyzes the development and application of hydrogen energy industry in recent years, covering many aspects such as laws and regulations, energy structure, realization path, and development status. Then, the research and development process of the hydrogen engine of the technical team of Dongfeng Motor Group Co., Ltd. R&D Institute Department is introduced, and the effective thermal efficiency of 45.04% is achieved. Finally, the future of hydrogen engine is further prospected.
Jin, Xiaoyan, Zhang, Shemin, Duan, Shaoyuan, Liu, Cong, Zhou, Hongli
Precise and Robust SoC Estimation Using Adaptive Filters-Based Techniques for Electric Trucks2024-28-015212/5/2024
The traction for zero emission vehicles in the transportation industry is creating a focus on Battery Electric vehicles (BEV) as one of the potential alternate powertrain sources. To operate BEV safely and efficiently battery operating conditions and health is of utmost importance. Battery management system (BMS) controller is needed for optimized and safe operation of high voltage (HV) battery. For correct behavior of BMS, accuracy of state of charge (SoC) estimation is important. SoC is an important and decisive factor for deciding operating limits such as current limits, voltage limits and battery operational range (charge-discharge interval). Inaccurate SoC estimation can accelerate battery aging and cause damage to it. The current state of art deploys coulomb counting technique for SoC calculation, this approach encounters challenges like sensor noises and initial SoC error (carried from the previous charge-discharge cycle). This paper mainly focuses on exploring various techniques to minimize errors in the SoC calculation. Extensions of Kalman filters are modelled, parameterized, and studied to negotiate the limitations of present SoC estimation techniques. Further, robustness against interference noise and initial error is carried out to ensure the filter performance. These simulation results are validated against actual test data for real time correlation.
Kumar, Raman, AHMAD, MD SAIF, Challa, Krishna, Ranjan, Ashish, Bayya, Madhuri
Low-carbon Hydrogen Use Across Economic Sectors and Global RegionsEPR202402611/25/2024
There is great recognition regarding the importance of hydrogen as an energy route for the decarbonization of road vehicles. Several countries are making large investments to create products, services, and infrastructures that allow hydrogen to be used as a clean source for propulsion, but there are still many open questions. This complete hydrogen chain involves production, transformation, transport, storage, and use. Although many initiatives are seeking global production, the use of low-carbon hydrogen is not yet economically competitive. Therefore, for this industry to establish itself, and acknowledging the characteristics of each region, there needs to be more intense coordination of efforts between the different industrial and political segments. Low-carbon Hydrogen Use Across Economic Sectors and Global Regions establishes premises for the hydrogen economy and its main environmental aspects. It also includes proposals and scenarios to establish a strategy that relates to production, transport, and application with a focus on global integration. Click here to access the full SAE EDGETM Research Report portfolio.
Adas, Camilo Abduch
Process Purifies Hydrogen Fuel Over a Broad Temperature RangeTBMG-5193611/1/2024
Hydrogen is considered one of the most promising clean energy sources. Hydrogen fuel cells offer high energy conversion efficiency and zero emissions. But the development of hydrogen fuel cells faces many challenges, including the issue of carbon-monoxide (CO) poisoning of the fuel cell electrodes.
SAE TOMORROW TODAY: Scaling Wireless EV Charging with SAE J29541348410/30/2024
How close is the EV industry to commercializing wireless charging? The answer lies in the SAE J2954 standard which establishes an industry-wide specification that defines the acceptable criteria for interoperability, electromagnetic compatibility, EMF, minimum performance, safety, and testing for wireless power transfer (WPT) of light-duty plug-in electric vehicles. For the latest insight, we sat down with Jesse Schneider, CEO/CTO, ZEV Station, and Chair, SAE Wireless Charging Taskforce for SAE J2954, and Ky Sealy, Engineering Fellow, WiTricity, and Subteam Lead of Wireless Charging Alignment for SAE J2954, to discuss the recent developments and the next generation of wireless power transfer. For more on the evolution of wireless charging adoption from ZEV Station and WiTricity, check out Episode 166 and Episode 114 in our back catalog. And if developing industry standards interests you, consider joining an SAE Committee. For more information, please email Standards Specialist, Dante Rahdar, at dante.rahdar@sae.org. We'd love to hear from you. Share your comments, questions and ideas for future topics and guests to podcast@sae.org. Don't forget to take a moment to follow SAE Tomorrow Today--a podcast where we discuss emerging technology and trends in mobility with the leaders, innovators and strategists making it all happen--and give us a review on your preferred podcasting platform. Follow SAE on LinkedIn, Instagram, Facebook, Twitter, and YouTube. Follow host Grayson Brulte on LinkedIn, Twitter, and Instagram.
Hineman, Marcie
Critical Mass: The One Thing You Need to Know About Green CarsR-57510/23/2024
In an era where climate change dominates global discourse, Felix Leach and Nick Molden dive deep into the complexity of vehicle emissions in their groundbreaking new book. Building on the insights from Felix's previous work, Racing Toward Zero, this new release confronts the bewildering landscape of automotive pollution with a clear, rigorous approach: what one piece of information can best describe the environmental impact of cars? Our digital age bombards us with information, yet meaningful understanding often eludes us, particularly when it comes to climate issues like road vehicle emissions. As simple solutions to such a complex problem remain elusive, Leach and Molden advocate for a sophisticated, yet accessible perspective. They propose a radical simplification of how we consider the environmental impact of cars and explore the multifaceted impacts of various vehicle powertrains, pushing beyond CO2 emissions to address broader environmental and societal concerns. The authors introduce the Molden-Leach Conjecture, a bold, universal solution that evaluates vehicles through a holistic lens. This conjecture offers a comprehensive framework to assess and regulate environmental impact, aiming to simplify complex choices for consumers and policymakers alike. They propose a new paradigm for taxing vehicles as we move away from fossil gasoline and diesel, enabling policymakers to address pollution and underpin tax revenues simultaneously. In a world where climate action is critical yet convoluted, Leach and Molden's book promises clarity and actionable insight. It's not just about finding answers-it's about finding the right ones. Join the journey to demystify automotive emissions and drive meaningful change. "As a former Secretary of State for the Environment and, later, Industry I welcome this contribution to the most important challenge of our time." Michael Heseltine, former Deputy Prime Minister of the United Kingdom
Leach, Felix, Molden, Nick
Hydrogen Engine Development toward Performance Parity with Conventional Fuel-Type Engines While Ensuring Ultralow Tailpipe Emissions03-17-08-00619/25/2024
The societies around the world remain far from meeting the agreed primary goal outlined under the 2015 Paris Agreement on climate change: reducing greenhouse gas (GHG) emissions to keep global average temperature rise to well below 20°C by 2100 and making every effort to stay underneath of a 1.5°C elevation. In 2020 direct tailpipe emissions from transport represented around 8 GtCO2eq, or nearly 15% of total emissions. This number increases to just under 10 GtCO2eq when indirect emissions from electricity and fuel supply are added, for a total share of roughly 18%. Following the current trend, direct and indirect emissions in transport could reach above 11 GtCO2eq by 2050. Roughly 76% of transport emissions are related to land-based passenger and freight road transport. Emissions from aviation and shipping account for the remaining 24% of 2020 emissions. Hydrogen (H2) is in this scenario considered to play a key role as a carbon-free and versatile energy carrier. Combustion of hydrogen in an ICE offers the potential to accelerate the introduction of carbon-neutral mobility in the short to medium term at competitive cost due to the utilization of well-proven and mature technology elements. Given the high technological maturity of internal combustion engines (ICEs), there is an increasing interest in ICEs powered by hydrogen as a CO2-free solution for on- and off-road vehicles as well as construction equipment. All along the development, the objectives were set to develop the right technological combination that offers power, torque, and transient response comparable to current diesel engine. The results shown demonstrate the great potentials of the hydrogen engine technology. The engine KPI are matching the ones from the diesel base engine while offering near-zero emission concept thanks to the alignment of engine control and aftertreatment system calibration.
Koerfer, Thomas, Durand, Thomas, Virnich, Lukas
Life Cycle Analysis of a PEM Fuel Cell System for Long-Haul Heavy-Duty Trucks2024-24-00209/18/2024
The European Union plans to reach net-zero greenhouse gas (GHG) emissions in 2050. In 2020, the transport sector significantly contributed to global energy-related GHG emissions, with heavy-duty vehicles (HDVs) responsible for a substantial portion of road transport emissions in the EU and a notable percentage of the EU’s total GHG emissions. Zero-emission vehicles (ZEVs), including fuel cell (FC) vehicles, are crucial for decarbonizing the transport sector to achieve climate neutrality. This paper aims at quantifying the environmental impacts of a 200kW proton exchange membrane FC system for long-haul HDVs with a 40-ton mass and 750 km driving range. The life cycle assessment (LCA) methodology was applied, and a life cycle model of the FC system was developed with a cradle-to-grave boundary. To ensure reproducibility and scalability, results are reported on a kW basis. A sensitivity analysis was performed on key parameters, including hydrogen production route, FC system production location, fuel consumption, FC system size, FC system replacement, and FC material composition. At the cradle-to-gate boundary, GHG emissions of the FC system ranged from 30.5 to 51.4 kg CO₂eq/kW. The catalyst was the most impactful component due to the presence of platinum, followed by the balance of plant. In the cradle-to-grave boundary, raw material extraction and production phases were negligible, while the use phase was the main driver of the overall impact of the FC system. Certain equivalences were observed when considering other impact categories.
Gentilucci, Gaia, Accardo, Antonella, Spessa, Ezio
Emission Optimization of the Cold Start Behavior of a CNG Engine with Electrically Heated Catalyst and Secondary Air Injection2024-24-00289/18/2024
Decarbonization and a continuous reduction in exhaust emissions from combustion engines are key objectives in the further development of modern powertrains. In order to address both aspects, the DE4LoRa research project is developing an innovative hybrid powertrain that is characterized by the highly flexible combination of two electric motors with a monovalent compressed natural gas (CNG) engine. This approach enables highly efficient driving in purely electric, parallel and serial operating modes. The use of synthetic CNG alone leads to a significant reduction in CO2 emissions and thus in the climate impact of the drivetrain. With CNG-powered engines in particular, however, methane and other tailpipe emissions of climate gases and pollutants must also be minimized. This is possible in particular through efficient exhaust gas aftertreatment and an effective operating strategy of the powertrain. This publication presents measurement results that examine the critical aspect of cold starts. The engine is operated with a three-way catalyst with a coating specially tailored to CNG as well as an electrically heated disk and secondary air injection. The powertrain operating strategy makes it possible to preheat the catalyst when the engine is not running, which enables the catalyst to reach higher temperatures prior to the engine start, thus effectively reducing methane slip and other emissions during cold start. The combination of electrical heating power, secondary air mass flow and pre-heating duration are three of the factors in the optimization carried out here. Added to this is an analysis of the most efficient and low-emission engine start using a serial operating mode.
Noone, Patrick, Herold, Tim, Beidl, Christian
Assessing Heavy Duty Vehicle CO 2 Emissions for Qualification as a Zero Emissions Vehicle2024-37-00076/12/2024
The global transportation industry, and road freight in particular, faces formidable challenges in reducing Greenhouse Gas (GHG) emissions; both Europe and the US have already enabled legislation with CO2 / GHG reduction targets. In Europe, targets are set on a fleet level basis: a CO2 baseline has already been established using Heavy Duty Vehicle (HDV) data collected and analyzed by the European Environment Agency (EEA) in 2019/2020. This baseline data has been published as the reference for the required CO2 reductions. More recently, the EU has proposed a Zero Emissions Vehicle definition of 3g CO2/t-km. The Zero Emissions Vehicle (ZEV) designation is expected to be key to a number of market instruments that improve the economics and practicality of hydrogen trucks. This paper assesses the permissible amount of carbon-based fuel in hydrogen fueled vehicles – the Pilot Energy Ratio (PER) – for each regulated subgroup of HDVs in the baseline data set. The analysis indicates that a PER of ~4% is required to address the key long-haul groups (5LH, 9LH and 10LH) and potentially some Regional Distribution vehicles, but that much lower PERs are required for most of the Regional and Urban Delivery vehicles in this group. The assessment then looks at the impact of the actual vehicle configuration and identifies features impacting the PER such as rear axle ratio; for example, an engine may be capable of meeting the Zero Emissions requirement, but rear axle ratios greater than 3 may still cause a specific vehicle configuration to exceed 3g/t-km of CO2. The paper concludes by assessing the existing technology options to meet the ZEV requirements and the current state of these technologies against the required PER target.
Mumford, David K., Williams, Graham, Leclercq, Nadege
Sustainable ecosystem model involves multiple partners24AUTP06_076/1/2024
Rooftop solar panels will soon power about 90% of PFG's Gilroy, California, operations, a starting point for cold food deliveries. The vehicles getting the various edibles and food-related products from the warehouse to restaurants, schools, hotels and other customers include new battery-electric Class 8 trucks that mate to trailers fitted with zero-emission transport refrigeration units (TRUs). “Our Gilroy, California, location is the pilot for how we intend to develop sustainable distribution centers,” said Jeff Williamson, senior vice president of operations for Richmond, Virginia-headquartered Performance Food Group (PFG). Williamson and others were recently interviewed by SAE Media following an Earth Day open house at the Gilroy site.
Buchholz, Kami
Unveiling the Potential of Hydrogen in a Downsized Gasoline Direct Injection Engine Performance and Emissions Experimental Study04-17-03-00155/11/2024
The transportation sector’s growing focus on addressing environmental and sustainable energy concerns has led to a pursuit of the decarbonization path. In this context, hydrogen emerges as a promising zero-carbon fuel. The ability of hydrogen fuel to provide reliable performance while reducing environmental impact makes it crucial in the quest for net zero targets. This study compares gasoline and hydrogen combustion in a single-cylinder boosted direct injection (DI) spark ignition engine under various operating conditions. Initially, the engine was run over a wide range of lambda values to determine the optimal operating point for hydrogen and demonstrate lean hydrogen combustion’s benefits over gasoline combustion. Furthermore, a load sweep test was conducted at 2000 rpm, and the performance and emission results were compared between gasoline and optimized hydrogen combustion. An in-depth analysis was conducted by varying fuel injection time and pressure. This enabled us to explore the effects of these variables on the fuel’s performance and emissions, providing valuable insights for further optimization. The key findings of this study are significant. They note that hydrogen fuel allows the engine to operate under lean conditions with stable combustion up to 3.8 lambda. Lean combustion produces higher engine thermal efficiency, low cyclic variability, and near-zero NOx emissions. According to the study, hydrogen combustion produces zero emissions of hydrocarbons (HC), carbon monoxide (CO), and carbon dioxide (CO2) under a wide range of operating conditions, making it a clean and environmentally friendly fuel source. During low loading, exhaust hydrogen slip is less than 1000 ppm. This slip drops below 500 ppm as the load increases. Finally, the study proved that hydrogen is more stable than gasoline at a stoichiometric level. This suggests that hydrogen could replace gasoline in some applications, which has major implications for alternative energy.
Mohamed, Mohamed, Biswal, Abinash, Wang, Xinyan, Zhao, Hua, Harrington, Anthony, Hall, Jonathan
Demonstration of Low Criteria Pollutant and Greenhouse Gas Emissions: Synergizing Vehicle Emission Reduction Technology and Lower Carbon Fuels2024-01-21214/9/2024
This study focuses on evaluation of various fuels within a conventional gasoline internal combustion engine (ICE) vehicle and the implementation of advanced emissions reduction technology. It shows the robustness of the implemented technology packages for achieving ultra-low tailpipe emissions to different market fuels and demonstrates the potential of future GHG neutral powertrains enabled by drop-in lower carbon fuels (LCF). An ultra-low emission (ULE) sedan vehicle was set up using state-of-the-art engine technology, with advanced vehicle control and exhaust gas aftertreatment system including a prototype rapid catalyst heating (RCH) unit. Currently regulated criteria pollutant emission species were measured at both engine-out and tailpipe locations. Vehicle was run on three different drive cycles at the chassis dynamometer: two standard cycles (WLTC and TfL) at 20°C, and a real driving emission (RDE) cycle at -7°C. Several EN228 compliant fuels, including lower-carbon fuel candidate, were tested. Fuels were formulated representing the distribution of volatility, C9 and higher aromatics (A9+), and C11 and higher aromatics (A11+) currently in the European market. The results show that with ULE technology, a significant reduction in tailpipe emissions is achievable across various test cycles and conditions. It was found that fuel property effects on tailpipe emissions are mitigated by the ULE test vehicle. However, the engine-out total hydrocarbon (THC) and particle number (PN) emission showed sensitivity to fuel formulation. Fuel mid-distillation range was a good general predictor of engine-out THC emissions. Engine-out PN emissions were not consistently correlated with any fuel properties. However, Yield Sooting Index (YSI) in combination with back-end volatility was correlated with PN emissions on two of three test cycles on this vehicle.
Storch, Michael, Singh, Ripudaman, Haubold, Sven, Voice, Alexander
Diagnostic Communication with Zero Emission Vehicles (ZEV) Using ISO 14229-5 (UDS on IP) and SAE J1979-3 (ZEV on UDS)2024-01-19854/9/2024
SAE J1979 and its “OBD Modes” served for the protection of our environment against harmful pollutants for decades, but due to regulatory adoption of Unified Diagnostic Services (UDS), SAE J1979 has now become a multiple part document series: SAE J1979 will be replaced by SAE J1979-2 for vehicles with combustion engines (ICEs) and by SAE J1979-3 for Zero Emission Vehicle (ZEV) propulsion systems. For ZEVs, emission-related failures will be replaced by ZEV propulsion-related failures. Both SAE J1979-2 and -3 are variants of ISO 14229 (UDS) but limited to emission-related and ZEV propulsion-related failures, respectively, and associated diagnostic data. These new diagnostic communication protocols are required by California Air Resources Board (CARB) but do not support vehicle-manufacturer-specific diagnostic applications like calibration or flash programming. For performance reasons of the flash process, the deployment of UDS on Internet Protocol (UDSonIP) as it is standardized in ISO 14229-5 became state-of-the art. This paper describes the basics of UDSonIP, Diagnostic communication over Internet Protocol (DoIP) and ZEVonUDS. It also covers how DoIP is used for diagnostic communication with the ZEV propulsion system to read the VIN. Finally, it provides a comparison between DoIP and Diagnostic communication over Controller Area Network (DoCAN), based on the analysis of a hex dump.
Subke, Peter, Heineman, Lindsey, Mayer, Julian
eFuels: An Alternative to the Alternative24AUTP04_014/1/2024
Low-carbon fuels promise greener alternatives, but can they deliver? Even as electric vehicles dominate today's alternative powertrain market for passenger cars, the future of how we will all someday drive without burning petroleum is cloudier than ever. To decarbonize transportation, governments and companies around the world are promoting various future technologies, including hydrogen and synthetic fuels, as alternatives to the alternative. In the U.S., the road to a hydrogen future recently hit a few road-blocks. In February 2024, Shell announced it would dramatically scale back its H2 refueling station plans in California and close some of its few stations. This dealt a blow to local H2-vehicle drivers as well as the state's plans for a robust hydrogen infrastructure. When Hyundai announced in October 2021 that it would support Shell's plans to add 48 additional H2 refueling stations in California, it said that “hydrogen refueling infrastructure growth is critical to rapidly increase consumer adoption of zero-emission fuel cell vehicles.”
Blanco, Sebastian
Fuel Cell Electric Metro Train Concept – Zero Emission Rail Transport Solution for Indian Cities2024-26-01791/16/2024
Indian cities are among the most polluted in the world. The transportation sector is one of the major sources of gaseous pollutants. In recent years, also the effects of climate change and global warming have been felt across the globe. India has therefore committed at the CoP26 summit in 2021 to reduce its CO2 emissions by 45% till the year 2030. The Indian automotive sector is already addressing the problem with implementation of the Stage 2 BS VI norms, CAFÉ & Stage V standards and pursuing rapid electrification with application of zero emission vehicles. India also has the largest rail network of Asia, and a significant proportion of greenhouse gases is emitted by this sector. Deployment of zero emission fuel cell trains would be one of the solutions to meet India’s emission reduction targets. Indian Railways has already started its journey towards zero emissions and has set a target to launch hydrogen fuel cell trains on some routes soon as part of the “Hydrogen for Heritage” initiative. In this study, the application of fuel cell technology in an Indian metro train is investigated. The dimensioning of the major powertrain components like the fuel cell system, HV battery pack, and the hydrogen storage system for the fuel cell train are presented. Also, a retrofit approach will be developed, which includes a packaging study of the major powertrain components in the engine and passenger coaches of the existing train. System simulations with validated models allow an assessment of the system weight and costs for the new fuel cell metro train.
Emran, Ashraf, Garg, Shivam, Mertes, Simon, Gautam, Anirudh, Schmidt, Marvin, Wick, Maximilian, Walters, Marius, Wagh, Sachin, Sharma, Vijay
Advance Thermal Management System for Electric Vehicle – An Indian Case Study2024-26-01261/16/2024
Climate change and global warming are one of the major challenges faced by the world today. A significant number of Indian cities rank among the most polluted globally, with vehicular emissions being the primary contributor. To address this issue, the Government of India is actively advocating for the adoption of zero-emission vehicles such as electric vehicles through policies and initiatives like FAME II [1], PMP and the National Mission for Transformative Mobility and Storage. The acceptance of electric vehicles is growing in the Indian market seeing more than 200% increase in sales in the year 2022 compared to 2021 with a large share of 2-wheelers, 3-wheelers and compact cars getting electrified. Further adoption of electrification on a much larger scale currently faces the major challenge of high overall vehicle cost compared to conventional vehicles, with the major contribution coming from the HV battery which is the costliest system on the electric vehicles. An electric vehicle with high energy efficiency can meet its driving range requirements with a relatively smaller battery size thereby leading to lower vehicle costs. Electric vehicle energy efficiency improvement can be achieved not only by reducing the losses at main powertrain components like electric motor, HV battery, transmission etc. or improved vehicle rolling resistance, aerodynamics but also by an energy optimized thermal management system. The presented study focuses on reducing the energy demand of the thermal management system of an electric vehicle. As a basis for the case study, one of the most sold electric vehicles in the Indian market was selected and assessed for its energy consumption. As a next step, the introduction of advanced technologies like optimized and innovative control strategies such as predictive thermal management control (e.g., intelligent pre-conditioning, cabin air circulation control and smart ventilation) for cooling, heat pump integration along with the heat harvesting strategies for heating were done to detail the potential reduction in energy consumption of the vehicle. In addition, integrative measures were also assessed to reduce the energy required for cabin air conditioning. Local climatization measures were also investigated for an efficient thermal management system. With the applied improvement solutions, the vehicle energy efficiency and driving range increased. All the simulations were performed on well validated GT SUITE simulation models from FEV.
Emran, Ashraf, Pawar, Bhushan, Chavan, Sagar, Hemkemeyer, David, Sharma, Vijay, Garg, Shivam, Franke, Kai
ZERO-EMISSION INTERNAL COMBUSTION ENGINESAE-PP-0036811/17/2023
A new concept of internal combustion engine has been developed. The purpose is to have an engine that can burn hydrocarbon fuels without discharging any greenhouse gas or other harmful substances into the atmosphere. The new engine, the zero-emission engine, inducts no air from the environment. Instead, the engine exhaust gas, with added oxygen, is used in performance of the combustion cycle. Carbon dioxide, the main byproduct of combustion is captured, stored, and unloaded during refueling for further storage, sequestration, or recycling. The zero-emission engine displacement can be significantly smaller than in a conventional air-inducting engine of equal power, with a significantly higher power density. The engine is unthrottled and it can operate with a much higher compression ratio without an increase in the cylinder temperature. The above concept also envisions recycling the captured carbon dioxide by using it with water to produce hydrocarbon fuel and oxygen that can be supplied back to the engine. In that case, an automobile and a refueling station form a closed-energy circuit, in which the internal combustion process produces carbon dioxide that is converted back into fuel at the refueling station (or other processing facility), and that fuel is delivered back to the vehicle. The engine operates in a carbon-neutral mode burning fuel that can be repeatedly used, regenerated, and reused again. This paper describes the above concept and reviews its advantages and disadvantages. It also describes an experimental vehicle system that has been built to evaluate and verify the feasibility of the concept and review the test results. The concept was judged to be feasible, and the experimental vehicle equipped with a zero-emission engine is operational. No exhaust gas is discharged into the atmosphere.
Schechter, Michael, schechter, victor
E/E Diagnostic Test Modes: Zero Emission Vehicle Propulsion Systems on UDS (ZEVonUDS)J1979-3_202310 (Current)10/6/2023
This document is intended to satisfy the data reporting requirements of standardization regulations in the United States and Europe, and any other market that may adopt similar requirements in the future. This document specifies: a Message formats for request and response messages. b Timing requirements between request messages from external test equipment and response messages from vehicles, and between those messages and subsequent request messages. c Behavior of both the vehicle and external test equipment if data is not available. d A set of diagnostic services, with corresponding content of request and response messages. e Standardized source and target addresses for clients and vehicle. This document includes capabilities required to satisfy OBD requirements for multiple regions, model years, engine types, and vehicle types. At the time of publication many regional regulations are not yet final and are expected to change in the future. This document makes no attempt to interpret the regulations and does not include applicability of the included diagnostic services and data parameters for various vehicle applications. The user of this document is responsible to verify the applicability of each section of this document for a specific vehicle, engine, model year, and region. SAE J1979-3 specifies diagnostic services, and both functionally addressed and physically addressed request/response messages required to be supported by motor vehicles and external test equipment for diagnostic purposes which pertain to motor vehicle emission-related data. Any external test equipment meeting the requirements of SAE J1978 is intended to be able to use these messages to retrieve ZEV propulsion-related information from the vehicle. The structure of this document is based on the structure of SAE J1979 for the convenience of users familiar with SAE J1979. Each section of this part of SAE J1979-3 which specifies additional detail to existing sections of ISO 15765-4 and SAE J1979 supersedes those specifications for their use under the scope of SAE J1979-2. When applicable, a reference to respective sections in SAE J1979-2 is made in this document. SAE J1979-3 references SAE J1979DA, which includes all Data Identifiers and Routine Identifiers.
Vehicle E E System Diagnostic Standards Committee
Improvement of Post-Oxidation for Low-Emission Engines through 3D-CFD Virtual Development2023-24-01078/28/2023
There is a growing need for low-emissions concepts due to stricter emission regulations, more stringent homologation cycles, and the possibility of a ban on new engines by 2035. Of particular concern are the conditions during a cold start, when the Three-Way Catalyst is not yet heated to its light-off temperature. During this period, the catalyst remains inactive, thereby failing to convert pollutants. Reducing the time needed to reach this temperature is crucial to comply with the more stringent emissions standards. The post oxidation by means of secondary air injection, illustrated in this work, is a possible solution to reduce the time needed to reach the above-mentioned temperature. The strategy consists of injecting air into the exhaust manifold via secondary air injectors to oxidize unburned fuel that comes from a rich combustion within the cylinder. This strategy can be implemented without major modifications to the engine's hardware or control system, making it an attractive option for retrofitting older engines or incorporating into new designs. The investigation was conducted experimentally and numerically, with test bench measurements and 3D-CFD simulations. The test bench data were helpful for validating and calibrating the 3D-CFD simulations, which employ two interrelated approaches. The first approach utilizes a full-engine mesh, which includes a 0D turbocharger model, to extrapolate reliable boundary conditions. The second approach uses a detailed exhaust model that includes the mentioned accurate boundary conditions and a chemical reaction mechanism. This paper presents the effects of post oxidation in two different engine operating points. Various secondary air injection strategies, including different temperatures and mass flows, and an alternative exhaust manifold design, are evaluated to assess potential improvements in post oxidation by means of 3D-CFD virtual development.
Pipolo, Mario, Kulzer, Andre, Chiodi, Marco, Moriyoshi, Yasuo
Modeling and Design of a PEM Fuel Cell System for Ferry Applications2023-24-01458/28/2023
The upcoming regulations to achieve zero-emission passenger transport present challenges for designing new ferry powertrains. The proposed work investigates the feasibility of using a Proton Exchange Membrane Fuel Cell (PEMFC) power system to power a long-haul ferry. The paper describes the zero-order cell model as well as the method for estimating cell degradation. The stack modeling, heat balance equations, and auxiliary modeling are also presented. The proposed model enables the simulation of the fuel cell under different operating conditions and includes the use of air or oxygen as an oxidizer. A thermal management strategy for the overall PEMFC system is also proposed. The model was calibrated on the characteristic curves of the PEMFC Ballard FCvelocity™ HD6 (150 kW) and validated by reproducing experimental results. Then, a real load profile of a ferry, as well as the proposed powertrain is considered as case study. The presented results are related to a single daily mission and its deterioration throughout the set mission cycle is finally presented.
Saponaro, Gianmarco, Stefanizzi, Michele, Franchini, Emanuele, Torresi, Marco, Camporeale, Sergio
Optimizing Hydrogen Fueling Infrastructure Plans on Freight Corridors for Heavy-Duty Fuel Cell Electric Vehicles13-05-01-00088/12/2023
The development of a future hydrogen energy economy will require the development of several hydrogen market and industry segments including a hydrogen-based commercial freight transportation ecosystem. For a sustainable freight transportation ecosystem, the supporting fueling infrastructure and the associated vehicle powertrains making use of hydrogen fuel will need to be co-established. This article introduces the OR-AGENT (Optimal Regional Architecture Generation for Electrified National Transportation) tool developed at the Oak Ridge National Laboratory, which has been used to optimize the hydrogen refueling infrastructure requirements on the I-75 corridor for heavy-duty (HD) fuel cell electric commercial vehicles (FCEV). This constraint-based optimization model considers existing fueling locations, regional-specific vehicle fuel economy and weight, vehicle origin and destination (O-D), and vehicle volume by class and infrastructure costs to characterize in-mission refueling requirements for a given freight corridor. The authors applied this framework to determine the ideal public access locations for hydrogen refueling (constrained by existing fueling stations), the minimal viable cost to deploy sufficient hydrogen fuel dispensers, and associated equipment, to accommodate a growing population of hydrogen fuel cell trucks. The framework discussed in this article can be expanded and applied to a larger interstate system, expanded regional corridor, or other transportation network. This article is the third in a series of papers that defined the model development to optimize a national hydrogen refueling infrastructure ecosystem for HD commercial vehicles.
Siekmann, Adam, Sujan, Vivek, Uddin, Majbah, Liu, Yuandong, Xie, Fei
OBD evolves for ICE and zero-emission propulsion systems23TOFHP08_068/1/2023
On-board diagnostics (OBD) systems support the protection of the environment against harmful pollutants such as carbon monoxide (CO), nitrogen oxide (NOx), hydrocarbons (HC) and particulate matters (PM) emitted by combustion engines. OBD regulations require passenger cars and light-, medium- and heavy-duty trucks to support a minimum set of diagnostic information to external (off-board) “generic” test equipment. For the purpose of communication, both the test equipment and the vehicle must support the same communication protocol stack. The communication protocol SAE J1979, also known as ISO 15031, that has been in use for decades will be replaced by SAE J1979-2 for vehicles with combustion engines and by SAE J1979-3 for zero-emission-vehicle (ZEV) propulsion systems.
Decarbonized Fuel Options for Civil AviationEPR20230126/13/2023
Drop-in replacement biofuels and electrofuels can provide net-zero CO2 emissions with dramatic reductions in contrail formation. Biofuels must transition to second-generation cellulosic feedstocks while improving land and soil management. Electrofuels, or "e-fuels,” require aggressive cost reduction in hydrogen production, carbon capture, and fuel synthesis. Hydrogen has great potential for energy efficiency, cost reduction, and emissions reduction; however, its low density (even in liquid form) combined with it’s extremely low boiling temperature mean that bulky spherical tanks will consume considerable fuselage volume. Still, emerging direct-kerosene fuel cells may ultimately provide a superior zero-emission, energy-dense solution. Decarbonized Power Options for Civil Aviation discusses the current challenges with these power options and explores the economic incentives and levers vital to decarbonization. Until common and enforceable global carbon pricing arrives, targeted national measures (e.g., mandates, price support, and finance) will be required. Click here to access the full SAE EDGETM Research Report portfolio.
Muelaner, Jody E.
A Climate-Change Scorecard for United States Non-commercial Driver Education13-05-01-00055/13/2023
In the United States (USA), transportation is the largest single source of greenhouse gas (GHG) emissions, representing 27% of total GHGs emitted in 2020. Eighty-three percent of these came from road transport, and 57% from light-duty vehicles (LDVs). Internal combustion engine (ICE) vehicles, which still form the bulk of the United States (US) fleet, struggle to meet climate change targets. Despite increasingly stringent regulatory mechanisms and technology improvements, only three US states have been able to reduce their transport emissions to the target of below 1990 levels. Fifteen states have made some headway to within 10% of their 1990 baseline. Largely, however, it appears that current strategies are not generating effective results. Current climate-change mitigation measures in road transport tend to be predominantly technological. One of the most popular measures in the USA is fleet electrification, receiving regulatory and fiscal encouragement from 45 US states and federal bills. However, zero-emission vehicles (ZEVs) might not be the climate change panacea for the transport sector. ZEVs are facing adoption issues ranging from affordability, equity, and charging infrastructure to vehicle class availability limitations. Despite increasing sales, US electric vehicle (EV) adoption has been behind the curve with a current market penetration of 4.5%. Outside of ZEVs, emission reduction in the US road transport sector has been sluggish. In road transport, which contributes the bulk of traffic-related air pollution (TRAP), there are clear gaps between policy targets, technology-based expectations, and actual results. For a sector that is struggling to meet climate change targets, broadening its scope of climate change mitigation measures for road transport would be useful. Driver behavior may be an underexplored strategy. Eco-driving is a known strategy and has been attributed to reducing TRAP by up to 50% (through nontechnological means) in various studies in the USA and across the world. If technological eco-driving measures are included, they can improve fuel economy in excess of 100%. But the extent to which it is included in driver education and licensing protocols in US states is unclear. This study, therefore, evaluates eco-driving in state-sponsored non-commercial Driving License Manuals (DLMs). Provisions in state DLMs were assessed based on the intent of the prescribed practices (collision safety, environmental exposure, or both), the extent to which these were included, and the strength of the recommended mechanisms (prescriptive or regulatory). The scores were converted into Grades A–D. The results are revealing. Despite thirty-three US states (66%) with extant climate change commitments, almost the same percentage (62%) of states received a “D” grade and entirely omitted to mention driver influence on fuel consumption and emissions. Only five states (10%) received an “A” grade with substantive eco-driving measures in their DLMs. There is thus significant scope for eco-driving content in DLMs, which can range from the state’s communicating climate change commitments to how drivers influence fuel consumption through their driving practices to empowering drivers with strategies they can adopt to save fuel and money and reduce emissions. This inclusion has the potential to improve vehicular fuel economy and help states meet their climate change goals. Driver education is the first step. Eco-driving principles can be further bolstered through subsequent inclusion in the driver training and testing phases of driver licensing.
Primlani, Ritu Vasu, Misra, Kajri
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