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The use of devices to reduce aerodynamic drag on large trailers and save fuel in long-haul, over-the-road freight operations has spurred innovation and prompted some trucking fleets to use them in combinations to achieve even greater gains in fuel-efficiency. This paper examines aerodynamic performance and potential drag reduction benefits of using trailer aerodynamic components in combinations based upon wind tunnel test data. Representations of SmartWay-verified trailer aerodynamic components were tested on a one-eighth scale model of a class 8 sleeper tractor and a fifty three foot, van trailer model. The open-jet wind tunnel employed a rolling floor to reduce floor boundary layer interference. The drag impacts of aerodynamic packages are evaluated for both van and refrigerated trailers. Additionally, the interactions between individual aerodynamic devices is investigated.

This paper discusses the several reasons why vehicles do not achieve the EPA MPG values in service, and makes a numerical estimate of the magnitude of the individual effects. In addition, methods for adjusting EPA MPG values to estimate road fuel economy performance are presented and discussed.

In response to more stringent emission requirements, catalysts for reducing NO to molecular nitrogen were developed. One of the most promising of these, the three-way catalyst, has been the subject of an EPA study to determine if it produces new tailpipe contaminants. This study and its results are described.

Due to its high efficiency and superior durability the diesel engine is again becoming a prime candidate for future light-duty vehicle applications within the United States. While in Europe the overall diesel share exceeds 40%, the current diesel share in the U.S. is 1%. Despite the current situation and the very stringent Tier 2 emission standards, efforts are being made to introduce the diesel engine back into the U.S. market. In order to succeed, these vehicles have to comply with emissions standards over a 120,000 miles distance while maintaining their excellent fuel economy. The availability of technologies such as high-pressure common-rail fuel systems, low sulfur diesel fuel, NOx adsorber catalysts (NAC), and diesel particle filters (DPFs) allow the development of powertrain systems that have the potential to comply with the light-duty Tier 2 emission requirements. In support of this, the U.S.

Methylcyclopentadienylmanganese tricarbonyl (MMT) while originally marketed in the late 50's and early 60's as a secondary antiknock to leaded fuels, is presently being marketed as a primary antiknock targeted for the EPA required lead-free gasoline grade tailored for use in catalyst-equipped vehicles. This paper reviews and discusses new information related to the effect of manganese gasoline additives on the performance of catalysts, regulated emissions, and several currently unregulated emissions. In addition, estimates of human exposures to automotive-generated manganese particulate and the toxicological characteristics of manganese are discussed as they related to an assessment of the potential public health consequences should manganese additives come into widespread use. EPA's position regarding the use of manganese additives is presented and discussed.

The U.S. Environmental Protection Agency (EPA) contracted with FEV, Inc. to estimate the per-vehicle cost of employing selected advanced efficiency-improving technologies in light-duty motor vehicles. The development of transparent, reliable cost analyses that are accessible to all interested stakeholders has played a crucial role in establishing feasible and cost effective standards to improve fuel economy and reduce greenhouse gas (GHG) emissions. The FEV team, together with engineering staff from EPA's National Vehicle and Fuel Emissions Laboratory, and FEV's subcontractor, Munro & Associates, developed a robust costing methodology based on tearing down, to the piece part level, relevant systems, sub-systems, and assemblies from vehicles ?with and without? the technologies being evaluated.

The U.S. Environmental Protection Agency (EPA) contracted with FEV, Inc. to estimate the per-vehicle cost of employing selected advanced efficiency-improving technologies in light-duty motor vehicles. The development of transparent, reliable cost analyses that are accessible to all interested stakeholders has played a crucial role in establishing feasible and cost effective standards to improve fuel economy and reduce greenhouse gas (GHG) emissions. The FEV team, together with engineering staff from EPA's National Vehicle and Fuel Emissions Laboratory, and FEV's subcontractor, Munro & Associates, developed a robust costing methodology based on tearing down, to the piece part level, relevant systems, sub-systems, and assemblies from vehicles “with and without” the technologies being evaluated.

This paper discusses the systems used by the Office of Mobile Source Air Pollution Control of EPA to measure and analyze automotive sulfuric acid emissions. This system involves mixing the entire vehicle exhaust with dilution air in a dilution tunnel. Sulfuric acid samples are collected by passing a small portion of the dilute exhaust through Fluoropore filters. The sulfuric acid content of the filters is determined by an automated barium chloranilate method. This paper also discusses test results from a number of advanced prototype vehicles including two stratified charge cars, a Dresser carburetor vehicle, three dual catalyst cars, and a 3-way catalyst car.

EPA published the first results from evaluations of electrically heated catalyst (EHC) technology for light-duty automotive applications. Since then, a number of automakers, suppliers, and government agencies have published results from their heated catalyst development and evaluation programs. EPA has evaluated a number of start catalyst systems incorporating an EHC start catalyst followed by a larger, conventional main catalyst. These systems have proven very effective at reducing cold start related emissions from methanol vehicles at low mileage. This paper compares the results from several EHC + main catalyst evaluations conducted by EPA.

This report describes in detail new test procedures designed to minimize test variability, and the resulting false failures of new technology vehicles. There are currently six promulgated test procedures. The new procedures differ from the current ones in that they include controlled preconditioning, second chance testing, and sampling and score selecting algorithms. These are intended to minimize the variability in testing conditions and thereby reduce false failures of clean vehicles. High emitting vehicles which have been escaping detection with the current test procedures may continue to do so under the new ones. It is EPA's hope that these new procedures will improve the possibility of using more stringent cutpoints and non-idle test modes in the future to detect these high emitters by eliminating the additional false failures that would otherwise occur by instituting such measures under current procedures.

In 2005, the United States Environmental Protection Agency (EPA) and Southwest Research Institute (SwRI) embarked on a mission to help the city of Beijing, China, clean its air. Working with the Beijing Environmental Protection Bureau (BEPB), the effort was a pilot diesel retrofit demonstration program involving three basic retrofit technologies to reduce particulate matter (PM). The three basic technologies were the diesel oxidation catalyst (DOC), the flowthrough diesel particulate filter (FT-DPF), and the wallflow diesel particulate filter (WF-DPF). The specific retrofit systems selected for the project were verified through the California Air Resources Board (CARB) or the EPA verification protocol [1]. These technologies are generally verified for PM reductions of 20-40 percent for DOCs, 40-50 percent for the FT-DPF, and 85 percent or more for the high efficiency WF-DPF.

The use of a partial flow sampling system (PFSS) to measure nonroad steady-state diesel engine particulate matter (PM) emissions is a technique for certification approved by a number of regulatory agencies around the world including the US EPA. Recently, there have been proposals to change future nonroad tests to include testing over a nonroad transient cycle. PFSS units that can quantify PM over the transient cycle have also been discussed. The full flow constant volume sampling (CVS) technique has been the standard method for collecting PM under transient engine operation. It is expensive and requires large facilities as compared to a typical PFSS. Despite the need for a cheaper alternative to the CVS, there has been a concern regarding how well the PM measured using a PFSS compared to that measured by the CVS. In this study, three PFSS units, including AVL SPC, Horiba MDLT, and Sierra BG-2 were investigated in parallel with a full flow CVS.

The potential discrepancy between the fuel economy shown on new vehicle labels and that achieved by consumers has been receiving increased attention of late. EPA has not modified its labeling procedures since 1985. It is likely possible that driving patterns in the U.S. have changed since that time. One possible modification to the labeling procedures is to incorporate the fuel economy measured over the emission certification tests not currently used in deriving the fuel economy label (i.e., the US06 high speed and aggressive driving test, the SC03 air conditioning test and the cold temperature test). This paper focuses on the US06 cycle and the possible incorporation of aggressive driving into the fuel economy label. As part of its development of the successor to the MOBILE emissions model, the Motor Vehicle Emission Modeling System (MOVES), EPA has developed a physically-based model of emissions and fuel consumption which accounts for different driving patterns.

The United States Environmental Protection Agency (EPA) has initiated Phase I of a regulatory program to control exhaust emissions of nonroad diesel engines over 37 kW. Central to any emissions regulation is the test procedure, which must include an appropriate test cycle. Based on actual in-use speed and estimated torque data collected from an agricultural tractor, a backhoe-loader, and a crawler tractor, three duty cycles were developed. Using an iterative process, comparison of chi-square statistical data was used to identify representative microtrips, segments of engine operation gathered during performance of selected activities. Representative microtrips for specific activities for a particular nonroad application were “strung” together to make up a test cycle. Before accepting the test cycle, data for the cycle was compared to statistical data used to characterize the raw data in an effort to validate that the cycle was representative of the raw data.

As part of the midterm evaluation of the 2022-2025 Light-Duty Vehicle Greenhouse Gas (GHG) Standards, the U.S. Environmental Protection Agency (EPA) developed simulation models for studying the effectiveness of 48V mild hybrid electric vehicle (MHEV) technology for reducing CO2 emissions from light-duty vehicles. Simulation and modeling of this technology requires a suitable model of the battery. This article presents the development and validation of a 48V lithium-ion battery model that will be integrated into EPA’s Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) vehicle simulation model and that can also be used within Gamma Technologies, LLC (Westmont, IL) GT-DRIVE™ vehicle simulations. The battery model is a standard equivalent circuit model with the two-time constant resistance-capacitance (RC) blocks.

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 desktop application was developed using MATLAB/Simulink. 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).

This, the fourteenth in this series of papers, examines trends in fuel economy, technology usage and estimated 0 to 60 MPH acceleration time for model year 1986 passenger cars. Comparisons with previous year's data are made for the fleet as a whole and using three measures of vehicle/engine size: number of cylinders, EPA car class, and inertia weight class. Emphasis on vehicle performance and fuel metering has been expanded and analysis of individual manufacturers has been deemphasized; comparisons of the Domestic, European, and Japanese market sectors are given increased emphasis.

This, the eleventh in a series of Papers on EPA fuel economy trends, emphasizes the current Model Year (1983) as usual, but also gives increased emphasis to trends in vehicle technology, including catalyst and transmission subclasses. Final “CAFE”* production volumes and MPG figures have been used to update the data bases through the 1980 Model Year, and an analytic method used in the past to allocate year-to-year fleet MPG changes to specific causes, such as weight mix shifts, has been reinstituted. Conclusions are presented on the relation between fuel economy and emission standards, catalyst types, and transmission types.

EPA new-model fuel economy figures are presented for passenger vehicles and light duty trucks (those with GVW ratings up to 8500 lbs). The 1981 models are emphasized, with some comparisons to prior years included. Reader familiarity with the EPA tests, data bases, and analytical methods is assumed. Principal two-way analyses include comparisons of domestic vs. import, gasoline vs. Diesel, and Federal (49-state) vs. California vehicles. Sales fractions for a number of vehicle and engine emission control design features are included. The principal finding is that increased use of newer vehicle and emission control technologies in 1981 has accompanied significant fuel economy gains in spite of the tougher 1981 emission standards.

Saturn Corporation and its suppliers are partnering with the U.S. Environmental Protection Agency (EPA) Design for the Environment (DfE) Program and the University of Tennessee (UT) Center for Clean Products and Clean Technologies (CCPCT) in a project to develop a model for life-cycle management (LCM). This paper presents key findings from the first phase of the project, a survey by Saturn of its suppliers to determine their interests and needs for a supply chain LCM project, and identifies framework strategies for successful LCM.