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As part of an ongoing assessment of the potential for reducing greenhouse gas (GHG) emissions of light-duty vehicles, the U.S. Environmental Protection Agency (EPA) has implemented an updated methodology for applying the results of full vehicle simulations to the range of vehicles across the entire fleet.

From its database of engine and vehicle benchmarking data EPA identified the most efficient, engines, transmissions and vehicle technologies, and then used ALPHA to model a midsized car incorporating combinations of these existing technologies which minimize GHG emissions. In a similar analysis, ALPHA was used to estimate the GHG emissions from future low-GHG technology packages potentially available in model year 2025. ...The Environmental Protection Agency’s (EPA’s) Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate greenhouse gas (GHG) emissions from light-duty vehicles[1]. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types with different powertrain technologies, showing realistic vehicle behavior, and auditing of all internal energy flows in the model. ...In preparation for the midterm evaluation of the light-duty GHG emission standards for model years 2022-2025, EPA is refining and revalidating ALPHA using newly acquired data from model year 2013-2015 engines and vehicles.

As GHG and fuel economy regulations of light-duty vehicles have become more stringent, advanced emissions reduction technology has extensively penetrated the US light-duty vehicle fleet. ...The Environmental Protection Agency (EPA) has previously used its Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) full vehicle simulation tool to evaluate the greenhouse gas (GHG) emissions of light-duty vehicles. ALPHA contains a library of benchmarked powertrain components that can be matched to specific vehicles to explore GHG emissions performance. ...ALPHA contains a library of benchmarked powertrain components that can be matched to specific vehicles to explore GHG emissions performance. Recently, EPA has updated the ALPHA model with key changes including the addition of new models for electrified vehicle architectures and a robust structure which allows batch processing of large numbers of simulations.

The growing demand for transportation fuels and the global emphasis on reducing greenhouse gas (GHG) emissions have led to increased interest in analyzing transport GHG emissions from the life-cycle perspective. ...To achieve net zero GHG emissions in Case 2, the GHG emissions of electricity generation need to be reduced by 88% of the current level. ...This paper conducts a comprehensive life-cycle analysis (LCA) of the GHG emissions associated with the methanol production process, utilizing data inventory from China in 2019.

The Environmental Protection Agency’s (EPA’s) Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate greenhouse gas (GHG) emissions from light-duty vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types with different powertrain technologies, showing realistic vehicle behavior, and auditing of internal energy flows in the model. ...In preparation for the midterm evaluation (MTE) of the 2017-2025 light-duty GHG emissions rule, ALPHA has been updated utilizing newly acquired data from model year 2013-2016 engines and vehicles. ...Simulations conducted with ALPHA provide data on the effectiveness of various GHG reduction technologies, and reveal synergies that exist between technologies. The ALPHA model has been validated against a variety of vehicles with different powertrain configurations and GHG reduction technologies.

At the same time, mandated improvements to greenhouse gas emissions (GHG) require that these NOX reductions be achieved without sacrificing fuel consumption and increasing GHG emissions. ...At the same time, mandated improvements to greenhouse gas emissions (GHG) require that these NOX reductions be achieved without sacrificing fuel consumption and increasing GHG emissions. The CARB demonstration program has progressed through several stages since it was initiated, and the Stage 3 Low NOX program completed in 2020 represents the culmination of these technology demonstration efforts. ...This effort, using a 2017 production diesel engine as a baseline, demonstrated a combination of technologies that enabled Low NOX emission levels near the 90% reduction target, while at the same time maintaining GHG emission rates at the same levels as the base engine. Previous publications have gone into detail regarding individual elements of the Stage 3 technology package.

., EPA and NHTSA have issued a joint proposed GHG rule that sets limits for CO2 and other GHGs from pick-up trucks and vans, vocational vehicles, semi-tractors, and heavy duty diesel engines. ...This work focuses on the new U.S. regulation of greenhouse gas (GHG) emissions from commercial vehicles and diesel engines and the most likely technologies to meet future anticipated standards while improving transportation freight efficiency. ...This paper discusses and compares different technologies to meet GHG regulations for diesel engines based on considerations of cost, complexity, real-world fidelity, and environmental benefit.

Nitrous oxide (N2O), with a global warming potential (GWP) of 297 and an average atmospheric residence time of over 100 years, is an important greenhouse gas (GHG). In recognition of this, N2O emissions from on-highway medium- and heavy-duty diesel engines were recently regulated by the US Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration’s (NHTSA) GHG Emission Standards. ...In recognition of this, N2O emissions from on-highway medium- and heavy-duty diesel engines were recently regulated by the US Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration’s (NHTSA) GHG Emission Standards. Unlike NO and NO2, collectively referred to as NOx, N2O is not a major byproduct of diesel combustion. ...Engine-based results show that N2O emissions for this nonroad engine and aftertreatment system are below the current 0.1 g/bhp·hr on-highway GHG standard. To better understand the processes which contribute to the system-level N2O emissions seen during engine testing, reactor-based experiments were conducted to elucidate the fundamental component-level mechanisms responsible for N2O formation.

Light Duty Vehicle corporate average fuel economy (CAFE), fuel economy label, and greenhouse gas (GHG) requirements are related but are very different. The fundamentals to obtain the data are the same, but to derive the required values, the final formulas have different components. ...This paper compiles the fundamentals of vehicle CAFE, fuel economy label, and GHG information. The intent is to provide a reference to the foundation of these requirements. This paper should not be used for compliance purposes and the actual regulations need to be referenced.

They are responsible for 50% of petroleum (oil) consumption and 60% of all greenhouse gas (GHG) emissions worldwide. The number of vehicles is forecasted to double by 2050. Therefore the environmental issues such as noise, emissions and fuel burn have become important for energy and environmental sustainability. ...The technologies related to reduction in energy requirements such as reducing the vehicle mass by using the high strength low weight materials and reducing the viscous drag by active flow control and smoothing the operational profile, and reducing the contact friction by special tire materials are discussed along with the portable energy sources for reducing the GHG emissions such as low carbon fuels (biofuels), Lithium-ion batteries with high energy density and stability, and fuel cells.

Regulations have been established for the monitoring and reporting of greenhouse gas (GHG) emissions and fuel consumption from the transport sector. Low carbon fuels combined with new powertrain technologies have the potential to provide significant reductions in GHG emissions while decreasing the dependence on fossil fuel. ...Low carbon fuels combined with new powertrain technologies have the potential to provide significant reductions in GHG emissions while decreasing the dependence on fossil fuel. In this study, a lean-burn ethanol-diesel dual-fuel combustion strategy has been used as means to improve upon the efficiency and emissions of a conventional diesel engine. ...Compared to a baseline diesel-only operation, the ethanol-diesel dual-fuel engine yielded up to 57% lower well-to-wheels GHG emissions. Moreover, the dual-fuel combustion strategy attained higher net indicated efficiency than the conventional diesel mode from 0.6 to 2.4 MPa IMEP, with a maximum value of 47.2% at 1.2 MPa IMEP.

The Advanced Light-Duty Powertrain and Hybrid Analysis tool (ALPHA) was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulator capable of analyzing various vehicle types combined with different powertrain technologies. ...The ALPHA tool was used to evaluate technology effectiveness and off-cycle technologies such as air-conditioning, electrical load reduction technology and road load reduction technologies of conventional, non-hybrid vehicles for the Midterm Evaluation of the 2017-2025 LD GHG rule by the U.S. Environmental Protection Agency (EPA) Office of Transportation and Air Quality (OTAQ). ...The developed 48 V mild hybrid electric vehicle model can be used to estimate the GHG emissions and fuel economy of 48 V mild hybrid electric vehicles over the EPA regulatory drive cycles and to estimate off-cycle GHG emissions.

Light-duty vehicle greenhouse gas (GHG) and fuel economy (FE) standards for MYs 2012-2025 are requiring vehicle powertrains to become much more efficient. ...One key technology strategy that vehicle manufacturers are using to help comply with GHG and FE standards is to replace naturally aspirated engines with smaller displacement “downsized” boosted engines.

The Environmental Protection Agency (EPA) has collected a variety of engine and vehicle test data to assess the effectiveness of new automotive technologies in meeting greenhouse gas (GHG) and criteria emission standards and to monitor their behavior in real world operation. EPA’s Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate GHG emissions from vehicles using various combinations of advanced technologies and has been refined using data from testing conducted at EPA’s National Vehicle and Fuel Emissions Laboratory. ...EPA’s Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate GHG emissions from vehicles using various combinations of advanced technologies and has been refined using data from testing conducted at EPA’s National Vehicle and Fuel Emissions Laboratory.

A large number of organizations are committing to science-based targets (SBTi) and are following roadmap strategies towards Greenhouse Gas (GHG) reduction including all value chain players such as material suppliers, component manufacturers and OEMs [3]. ...These components themselves consume energy, and therefore are a cause of GHG emissions during their use. To quantify their contributions and help corporations progress towards decarbonization strategies there is a need for robust use phase calculation methodology. ...Existing global methods for calculating use phase emissions, such as Green House Gas (GHG) Protocol (version 1.0), provide a good framework, but still have uncertainties in its practical application.

The engine was operated over simulated EPA city and highway test cycles to assess the greenhouse gas (GHG) emissions performance in the context of EPA’s LD GHG standards through year 2025....As part of its technology assessment for the upcoming midterm evaluation (MTE) of the 2022-2025 Light-Duty Vehicle Greenhouse Gas (LD GHG) emissions standards, EPA has been benchmarking engines and transmissions to generate inputs for use in its Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) model, a physics-based, forward-looking, full vehicle computer simulation tool.

Environmental Protection Agency’s (EPA’s) Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate greenhouse gas (GHG) emissions from light-duty vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types with different powertrain technologies, showing realistic vehicle behavior, and auditing of all energy flows in the model. ...In preparation for the midterm evaluation (MTE) of the 2017-2025 light-duty GHG emissions rule, ALPHA has been refined and revalidated using newly acquired data from model year 2013-2016 engines and vehicles. ...A simple model based only on a steady-state fuel map will yield fuel consumption and GHG emissions lower than what is measured during a chassis dynamometer test due to a variety of factors present during transient operation.

Complete engine maps, transmission efficiencies, and vehicle data were used as inputs into the GT-DRIVE+ vehicle model to estimate fuel economy, greenhouse gas (GHG) and NOx emissions of a vehicle equipped with a 12-volt start-stop system. The model-simulated fuel economy, GHG and NOx emissions, engine torque, engine speed, and vehicle speeds were all in good agreement with the on-road measured fuel economy, GHG and NOx emissions from the PEMS vehicle test data. ...The model-simulated fuel economy, GHG and NOx emissions, engine torque, engine speed, and vehicle speeds were all in good agreement with the on-road measured fuel economy, GHG and NOx emissions from the PEMS vehicle test data. ...The model-simulated fuel economy, GHG and NOx emissions, engine torque, engine speed, and vehicle speeds were all in good agreement with the on-road measured fuel economy, GHG and NOx emissions from the PEMS vehicle test data.

Use of natural gas-diesel dual-fuel (NDDF) combustion in compression ignition engines is a method of reducing the net greenhouse gas (GHG) and particulate matter (PM) emissions of these engines. Compressed natural gas (NG) is injected into the intake manifold of the engine and the air-NG mixture is ignited by a direct injection of diesel in the cylinder. ...Use of the insert causes the GHG emissions to increase and decrease for diesel and NDDF combustion respectively. Additionally, use of the insert causes the NOx emissions to remain similar and increase for diesel and NDDF combustion respectively. ...By using low levels of exhaust gas recirculation, the NOx emissions of NDDF combustion can be reduced without significant impact on the GHG or PM emissions when compared to diesel combustion.

Both announced new legislation for CO2, Greenhouse Gas (GHG) Phase II. CARB is also planning additional Ultra Low NOx regulations. Both regulations are significant and will require a number of technologies to be used in order to achieve the challenging limits.