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Beginning in 2007, heavy-duty engine manufacturers in the U.S. have been responsible for verifying the compliance on in-use vehicles with Not-to-Exceed (NTE) standards under the Heavy-Duty In-Use Testing Program (HDIUT). This in-use testing is conducted using Portable Emission Measurement Systems (PEMS) which are installed on the vehicles to measure emissions during real-world operation. A key component of the HDIUT program is the generation of measurement allowances which account for the relative accuracy of PEMS as compared to more conventional, laboratory based measurement techniques. A program to determine these measurement allowances for gaseous emissions was jointly funded by the U.S. Environmental Protection Agency (EPA), the California Air Resources Board (CARB), and various member companies of the Engine Manufacturer's Association (EMA).

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.

On-vehicle proof-of-concept testing was conducted to evaluate the ability of the dual oxygen sensor catalyst evaluation method to identify serious losses in catalyst efficiency under actual vehicle operating conditions. The dual oxygen sensor method, which utilizes a comparison between an upstream oxygen sensor and an oxygen sensor placed downstream of the catalyst, was initially studied by the Environmental Protection Agency (EPA) under steady-state operating conditions on an engine dynamometer and reported in Clemmens, et al. (1).* At the time that study was released, questions were raised as to whether the technological concepts developed on a test fixture could be transferred to a vehicle operating under normal transient conditions.

There has been considerable interest in applying remote measuring methods to sample in-use vehicle emissions, and to characterize fleet emission behavior. A Remote Sensing Device (RSD) was used to measure on-road carbon monoxide (CO) emissions from approximately 350 in-use vehicles that had undergone transient mass emission testing at a centralized I/M lane. On-road hydrocarbon (HC) emissions were also measured by the RSD on about 50 of these vehicles. Analysis of the data indicates that the RSD identified a comparable number of the high CO emitters as the two speed I/M test only when an RSD cutpoint much more stringent than current practice was used. Both RSD and I/M had significant errors of omission in identifying High CO Emitters based on the mass emission test. The test data were also used to study the ability of the RSD to characterize fleet CO emissions.

As part of the U.S. Environmental Protection Agency’s (EPA’s) continuing assessment of advanced light-duty (LD) automotive technologies to support the setting of appropriate national greenhouse gas (GHG) standards and to evaluate the impact of new technologies on in-use emissions, a 2016 Honda Civic with a 4-cylinder 1.5-liter L15B7 turbocharged engine and continuously variable transmission (CVT) was benchmarked. The test method involved installing the engine and its CVT in an engine-dynamometer test cell with the engine wiring harness tethered to its vehicle parked outside the test cell. Engine and transmission torque, fuel flow, key engine temperatures and pressures, and onboard diagnostics (OBD)/Controller Area Network (CAN) bus data were recorded.

Plug-in hybrid electric vehicles (PHEVs) have the ability to significantly reduce petroleum consumption. Argonne National Laboratory (Argonne), working with the FreedomCAR and Fuels Partnership, helped define the battery requirements for PHEVs. Previous studies demonstrated the impact of the vehicle's characteristics, such as its class, mass, or electrical accessories, on the requirements. However, questions on the impact of drive cycles remain outstanding. In this paper, we evaluate the consequences of sizing the electrical machine and the battery to follow standard drive cycles, such as the urban dynamometer driving schedule (UDDS), as well as real-world drive cycles in electric vehicle (EV) mode. The requirements are defined for several driving conditions (e.g., urban, highway) and types of driving behavior (e.g., smooth, aggressive).

Twenty in-use vehicles that had failed the I/M test in the State of Michigan were inspected for engine mechanical condition as well as the state of the emission control system. Mass emission tests were conducted before and after repairs to the emission control system. The internal engine condition (i.e., high or low levels of cylinder leakage, or compression difference) showed little effect on the ability of the repaired vehicles to achieve moderate mass emission levels. Nine of the twenty vehicles were recruited after three years, and with the exception of tampering, the original emission control system repairs proved to be durable.

Simple tests were performed to investigate the operating characteristics of zirconia galvanic cells (lambda sensors) in automotive closed loop “three-way” emission control systems. Commercially available cells were exposed to typical gaseous components of exhaust gas mixtures. The voltages generated by the cells were at their maximum values when hydrogen, and, in some instances, carbon monoxide, was available for reaction with atmospheric oxygen that migrated through the cells' ceramic thimbles in ionic form. This dependence of galvanic activity on the availability of these particular reducing agents indicated that the cells were voltaic devices which operated as oxidation/reduction reaction cells, rather than simple oxygen concentration cells.

The Schatz Heat Battery stores excess heat energy from the engine cooling system during vehicle operation. This excess energy may be returned to the coolant upon the ensuing cold start, shortening the engine warm-up period and decreasing cold start related emissions of unburned fuel and carbon monoxide (CO). A Heat Battery was evaluated on a test vehicle to determine its effect on unburned fuel emissions, CO emissions, and fuel economy over the cold start portion (Bag 1) of the Federal Test Procedure (FTP) at 24°C and -7°C ambient conditions. The Heat Battery was mounted in a vehicle fueled alternately with indolene clear (unleaded gasoline) and M85 high methanol blend fuels. Several Heat Battery/coolant flow configurations were evaluated to determine which would result in lowest cold start emissions.

Eleven experienced commercial automotive technicians were recruited and trained to repair IM240 emission failures using a specially developed 30 hour course. The training course emphasized the use of an oscilloscope and a flow chart and wave form strategy to repair vehicles. Each technicians' performance was evaluated based on the repair of three or four in-use Arizona IM240 failures. Pre-training and post-training written tests were also administered. Results from this limited study were encouraging. After the technician training, HC and CO emission levels were reduced by 69% and NOx by 58%. More importantly, most of the technicians learned some new and useful diagnostic and equipment skills which they can immediately apply to their businesses. They also became more motivated to tackle the challenge of repairing vehicles to low transient emissions, and aware of the existence and use of new sophisticated diagnostic tools such as oscilloscopes.

High mileage vehicles (in excess of 50,000 miles) contribute more than half of all vehicular emissions. With the new catalytic converter equipped cars, the proportional contribution of these vehicles may be even higher than for pre-catalyst vehicles. Thus a substantial portion of motor vehicle related air pollution may be caused by vehicles not subject to the manufacturer directed provisions of the Clean Air Act. This paper presents a modeling effort based on hypotheses and some preliminary data, and suggests some alternatives to combat this potential problem.

The increased interest in use of methanol makes it important to determine what levels of methanol and formaldehyde emissions may be acceptable. This paper reviews the available health data for methanol and formaldehyde to define what approximate ranges of concentrations, termed ranges of concern, could be acceptable from a toxicological viewpoint. Air quality models are then used to predict the in-use fleet average exhaust emission levels in localized situations (heavily impacted by mobile sources) corresponding to these ranges of concern. Using predicted fleet compositions, approximate target emission levels are given for the light-duty portion of the fleet which could yield these fleet averages. Finally, there is a brief summary of available methanol and formaldehyde emissions data from neat methanol-fueled vehicles which are compared to the target levels.

This, the thirteenth in a series of papers on trends in EPA fuel economy, covers both passenger cars and light trucks and concentrates on the current model year, 1985. It differs from previous papers in two ways: 1) Model years 1975, 1980 and 1985 are highlighted, with the model years in between these rarely discussed; 2) The progress of the industry, as a whole, in improving fuel economy since 1975 is emphasized, and individual manufacturer data are de-emphasized. Conclusions are presented on the trends in fuel economy of the car and light truck fleets; the Domestic, European and Japanese market sectors; and various vehicle classes.

The application of resistive materials as part of an exhaust emission control system is presented and discussed. The importance of cold start emissions is emphasized, and results are presented from experiments conducted with two different conductive materials. Most of the testing was conducted using methanol as the fuel, although some tests were run using gasoline-fueled vehicles.

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.

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.

Today’s motor vehicles are approaching the complexity of aircraft and spacecraft, but have a slightly different set of variables for the human operator; the driver. Gravitational forces rarely vary significantly for the vehicle driver; the ability to alter the trajectory usually exists; and refueling opportunities are seldom mission-limiting. Yet the driver is performing in an abnormal, dynamic environment with uncontrolled events and potential life-threatening outcomes just like the aviator or astronaut. Defining and managing ‘acceptable risk’ in the high performance environments of space and aviation continues to challenge today’s engineers and human factors researchers. In the automotive industry, engineers have traditionally approached this challenge by insuring the vehicle design is robust enough to accommodate the full range of potential operators.

Three alternatives to internal combustion vehicles currently being researched, developed, and commercialized are electric, hybrid electric, and fuel-cell vehicles. A total life-cycle inventory for an alternative vehicle must include factors such as the impacts of car body materials, tires, and paints. However, these issues are shared with gasoline-powered vehicles; the most significant difference between these vehicles is the power source. This paper focuses on the most distinct and challenging aspect of alternative-fuel vehicles, the power sources. The life-cycle impacts of battery systems for electric and hybrid vehicles are assessed. Less data is publicly available on the fuel cell; however, we offer a preliminary discussion of the environmental issues unique to fuel cells. For each of these alternative vehicles, a primary environmental hurdle is the consumption of materials specific to the power sources.

In 2015 the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Transportation's National Highway Traffic Safety Administration (NHTSA) proposed a new steady-state engine dynamometer test procedure by which heavy-duty engine manufacturers would be required to create engine fuel rate versus engine speed and torque “maps”.[1] These maps would then be used within the agencies' Greenhouse Gas Emission Model (GEM)[2] for full vehicle certification to the agencies' proposed heavy-duty fuel efficiency and greenhouse gas (GHG) emissions standards. This paper presents an alternative to the agencies' proposal, where an engine is tested over the same duty cycles simulated in GEM. This paper explains how a range of vehicle configurations could be specified for GEM to generate engine duty cycles that would then be used for engine testing.