Search Results

By almost any definition, technology has penetrated the U.S. light-duty vehicle fleet significantly in conjunction with the increased stringency of fuel economy and GHG emissions regulations. The physical presence of advanced technology components provides one indication of the efforts taken to reduce emissions, but that alone does not provide a complete measure of the benefits of a particular technology application.

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 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.

This paper quantifies the potential of electric propulsion systems to reduce petroleum use and greenhouse gas (GHG) emissions in the 2030 U.S. light-duty vehicle fleet. The propulsion systems under consideration include gasoline hybrid-electric vehicles (HEVs), plug-in hybrid vehicles (PHEVs), fuel-cell hybrid vehicles (FCVs), and battery-electric vehicles (BEVs). ...Well-to-wheel energy and GHG emissions of future vehicle technologies were estimated by integrating the vehicle technology evaluation with assessments of different fuel pathways. ...However, continued reliance on fossil-fuels without effective carbon capture and sequestration for producing electricity and hydrogen constrain the GHG emission and energy reductions to about 60% below that of present-day spark-ignition technology.

Hybrid technology has the potential to enable dramatic reductions in greenhouse gases (GHG), such as the California goal of reducing GHG by 80 percent from 1990 levels by 2050. As a result it is expected that hybrid systems will occupy a growing proportion of the market. ...In this presentation, Ricardo will present a process for evaluating the impact that a hybrid system which has been optimised to minimise GHG emission over a specified drive-cycle will have on the effectiveness of engine OBD monitors. ...The optimisation process generates torque split, mode and gear changes required to minimise GHG emissions. This optimal engine-transmission-machine on-time profile is automatically analysed to generate the impact on the engine OBD system.

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.

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.

The Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles [1]. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types combined with different powertrain technologies. ...As a result of the model refinements and in preparation for the mid-term evaluation of the 2017-2025 LD GHG rule, we are revalidating the model with newly acquired vehicle data. This paper presents the benchmarking, modeling and continued testing of a 2013 Chevy Malibu 1LS.

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.

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.

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.

This paper explores the potential for reducing transport-related greenhouse gas (GHG) emissions by introducing high-efficiency spark-ignition engines with a dual-fuel injection system to customize the octane of the fuels based on real-time engine requirements. ...A Well-to-Wheels (W-t-W) GHG emissions assessment was conducted to estimate the overall emissions benefits of the dual fuel system. ...However, if a pathway for naphtha and oxygenate are chosen different than petroleum source, for example, natural gas feed Fischer-Tropsch naphtha and coal base methanol, GHG emissions are worse than baseline case. When the dual fuel system was combined with downsized boosted engine technology, synergic benefit was obtained maximum 30% W-t-W CO2eq reduction (15% from downsizing, 10% from mitigating knock via a high octane component and 5% from minimizing octane upgrade process in the refinery).

The Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles [1]. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types combined with different powertrain technologies. ...As a result of the model refinements and in preparation for the mid-term evaluation (MTE) of the 2022-2025 LD GHG emissions standards, the model is being revalidated with newly acquired vehicle data. In the effort to model the current and future US Light-Duty fleet there are times when complete and exact engine and powertrain component data are unavailable and must be approximated using components with comparable levels of performance and technology.

As part of the midterm evaluation of the 2022-2025 light-duty GHG emissions rule, the Environmental Protection Agency (EPA) has been evaluating fuel efficiency data from tests on newer model engines and vehicles. ...The data is used as inputs to an EPA vehicle simulation model created to estimate greenhouse gas (GHG) emissions from light-duty vehicles. The Advanced Light Duty Powertrain and Hybrid Analysis (ALPHA) model is a physics-based, full vehicle computer simulation capable of analyzing various vehicle types with different powertrain technologies and showing realistic vehicle behavior and auditing of all internal energy flows in the model.

The Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles [1]. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types combined with different powertrain technologies. ...As a result of the model refinements and in preparation for the mid-term evaluation (MTE) of the 2022-2025 LD GHG emissions standards, the model is being revalidated with newly acquired vehicle data. This paper presents an analysis of the effects of varying the absolute and relative gear ratios of a given transmission on carbon emissions and performance.

As part of its midterm evaluation of the 2022-2025 light-duty greenhouse gas (GHG) standards, the Environmental Protection Agency (EPA) has been acquiring fuel efficiency data from testing of recent engines and vehicles. ...The benchmarking data are used as inputs to EPA’s Advanced Light Duty Powertrain and Hybrid Analysis (ALPHA) vehicle simulation model created to estimate GHG emissions from light-duty vehicles. For complete powertrain modeling, ALPHA needs both detailed engine fuel consumption maps and transmission efficiency maps.

The Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created by EPA to estimate greenhouse gas (GHG) emissions from light-duty (LD) vehicles [1]. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types combined with different powertrain technologies.

The benchmarking data were used as inputs to EPA’s Advanced Light-duty Powertrain and Hybrid Analysis (ALPHA) vehicle simulation model to estimate GHG emissions from light-duty vehicles. ALPHA requires both detailed engine fuel consumption maps and transmission torque loss maps.