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A 2001 General Motors 4.3 liter V-6 marine engine was baseline emissions tested and then equipped with catalysts. Emission reduction effects of exhaust gas recirculation (EGR) were also explored. Because of a U.S. Coast Guard requirement that inboard engine surface temperatures be kept below 200°F, the engine's exhaust system, including the catalysts, was water-cooled. Engine emissions were measured using the ISO-8178-E4 5-mode steady-state test for recreational marine engines. In baseline configuration, the engine produced 16.6 g HC+NOx/kW-hr, and 111 g CO/kW-hr. In closed-loop control with catalysts, HC+NOx emissions were reduced by 75 percent to 4.1 g/kW-hr, and CO emissions were reduced by 36 percent to 70 g/kW-hr of CO. The catalyzed engine was then installed in a Sea Ray 190 boat, and tested for water reversion on both fresh and salt water using National Marine Manufacturers Association procedures.

This paper describes a method used to compare the emissions from transient operation of an engine with the emissions from steady state operating modes of the engine. Weightings were assigned to each mode based on the transient cycle under evaluation. The method of assigning the weightings for each mode took into account several factors, including the distance between each second of the transient cycle's speed-and-torque point requests (in a speed vs. torque coordinate system) and the given mode. Two transient cycles were chosen. The transient cycles were taken from actual in-use data collected on nonroad engines during in-field operation. The steady state modes selected were based on both International Standard Organization (ISO) test modes, as well as, augmentation based on contour plots of the emissions from nonroad diesel engines. Twenty-four (24) steady-state modes were used. The transient cycle's speed-and-torque points are used to weight each steady state mode in the method.

In comparison to the state of knowledge of standard internal combustion vehicles, there is relatively little known on how to best implement component sub-systems and best integrate these systems together to create a hybrid electric vehicle.

Studies of emissions from vehicles equipped with catalysts have shown that some unregulated emissions can increase when a catalyst is used. One example of this is sulfuric acid, which has been studied extensively. Other unregulated emissions include ammonia and hydrogen cyanide. In a number of studies, these unregulated pollutant emissions have been measured from light-duty vehicles and heavy-duty engines. These emission levels were used in air quality dispersion models to predict the resultant air quality levels. The ambient concentrations predicted for each pollutant were then compared to suggested concentrations at which adverse health effects may be found to determine if additional monitoring or control would be indicated for these pollutants. It was determined that mobile source emissions of sulfuric acid, hydrogen cyanide, and ammonia do not in general result in ambient levels of concern for the air quality situations studied.

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.

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.

The advent of emission control technology has resulted in significant changes in both the total mass and detailed patterns of hydrocarbons emitted from automobiles. Emission rates of 56 hydrocarbons from 22 motor vehicles, including catalyst and noncatalyst configurations, were determined for the Federal Urban Driving Cycle. An increased relative abundance of methane is indicated for vehicles equipped with oxidation catalysts. In view of the photochemically non-reactive nature of methane, simple and economic procedures for determination of vehicle nonmethane hydrocarbon emission rates are evaluated. In general the procedures evaluated require independent total hydrocarbon and methane analysis, with the nonmethane hydrocarbon level calculated by difference. The procedures are evaluated by comparison of indicated nonmethane hydrocarbon emission rates with rates obtained by summation of individual compound rates determined by advanced gas chromatographic procedures.

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.

A Methanol catalyst test program has been conducted in two phases. The purpose of Phase I was to determine whether a base metal or lightly-loaded noble metal catalyst could reduce Methanol engine exhaust emissions with an efficiency comparable to conventional gasoline engine catalytic converters. The goal of Phase II was the reduction of aldehyde and unburned fuel emissions to very low levels by the use of noble metal catalysts with catalyst loadings higher than those in Phase I. Catalysts tested in Phase I were evaluated as three-way converters as well as under simulated oxidation catalyst conditions. Phase II catalysts were tested as three-way converters only. For Phase I, the most consistently efficient catalysts over the range of pollutants measured were platinum/rhodium configurations. None of the catalysts tested in Phase I were able to meet a NOx level of 1 gram per mile when operated in the oxidation mode.

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).

This paper describes the development of adjustment factors applicable to the EPA City and Highway MPG values. The paper discusses the data bases used, and the analytical methods employed to arrive at adjustment factors of 0.90 for the EPA City MPG value and 0.78 for the EPA Highway MPG value.

As part of the U.S. Environmental Protection Agency’s (EPA’s) continuing assessment of advanced light-duty automotive technologies in support of regulatory and compliance programs, a development project was started to study various test methods to benchmark Electric Drive Units (EDUs) consisting of an electric motor, inverter and a speed-reduction gearset. Several test methods were identified for consideration, including both in-vehicle testing of the complete EDU and stand-alone testing of the EDU and its subcomponents after removal from the vehicle. In all test methods explored, sweeps of speed and torque test points were conducted while collecting key EDU data required to determine efficiency, including motor torque and speed, direct current (DC) battery voltage and current into the inverter, and three-phase alternating current (AC) phase voltages and currents out of the inverter and into the electric motor.

In designing a regulatory vehicle simulation program for determining greenhouse gas (GHG) emissions and fuel consumption, it is necessary to estimate the performance of technologies, verify compliance with the regulatory standards, and estimate the overall benefits of the program. The agencies (EPA/NHTSA) developed the Greenhouse Gas Emissions Model (GEM) to serve these purposes. GEM is currently being used to certify the fuel consumption and CO2 emissions of the Phase 1 rulemaking for all heavy-duty vehicles in the United States except pickups and vans, which require a chassis dynamometer test for certification. While the version of the GEM used in Phase 1 contains most of the technical and mathematical features needed to run a vehicle simulation, the model lacks sophistication. For example, Phase 1 GEM only models manual transmissions and it does not include engine torque interruption during gear shifting.

Emissions of six 32 passenger transit buses were characterized using one of the West Virginia University (WVU) Transportable Heavy Duty Emissions Testing Laboratories, and the fixed base chassis dynamometer at the Colorado Institute for Fuels and High Altitude Engine Research (CIFER). Three of the buses were powered with 1997 ISB 5.9 liter Cummins diesel engines, and three were powered with the 1997 5.9 liter Cummins natural gas (NG) counterpart. The NG engines were LEV certified. Objectives were to contrast the emissions performance of the diesel and NG units, and to compare results from the two laboratories. Both laboratories found that oxides of nitrogen and particulate matter (PM) emissions were substantially lower for the natural gas buses than for the diesel buses. It was observed that by varying the rapidity of pedal movement during accelerations in the Central Business District cycle (CBD), CO and PM emissions from the diesel buses could be varied by a factor of three or more.

The U.S. Environmental Protection Agency (EPA) formed a Heavy-Duty Engine Working Group (HDEWG) in the Mobile Sources Technical Advisory Subcommittee in 1995. The goal of the HDEWG was to help define the role of the fuel in meeting the future emissions standards in advanced technology engines (beyond 2004 regulated emissions levels). A three-phase program was developed. This paper presents the results of the statistical analysis of the data collected in the Phase II program. Included is a description of the design of the fuel test matrix, and a listing of the regression equations developed to predict emissions as a function of fuel density, cetane number, monoaromatics, and polyaromatics. Also included is a description of selected analyses of the emissions from a smaller set of fuel data that allowed direct comparison of the effects of natural and boosted cetane number.

The effect of diesel cetane number, total aromatic content T90, and fuel nitrogen content on regulated emissions (HC, CO, NOx, and PM) from a 1991 DDC Series 60 engine were measured Emissions tests were conducted using the EPA heavy-duty transient test (CFR 40 Part 86 Subpart N) at a laboratory located 5,280 feet (1609 m) above sea level. The objective of this work was to determine if the effect of fuel chemistry at high altitude is similar to what is observed at sea level and to examine the effect of specific fuel chemistry variables on emissions. An initial tea series was conducted to examine the effect of cetane number and aromatics. Transient emissions for this test series indicated much higher (50 to 75%) particulate emissions at high altitude than observed on the same model engine and similar fuels at sea level.

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.

Natural gas presents several challenges to engine manufacturers for use as a heavy-duty, lean burn engine fuel. This is because natural gas can vary in composition and the variation is large enough to produce significant changes in the stoichiometry of the fuel and its octane number. Similarly, operation at high altitude can present challenges. The most significant effect of altitude is lower barometric pressure, typically 630 mm Hg at 1600 m compared to a sea level value of 760 mm. This can lower turbocharger boost at low speeds leading to mixtures richer than desired. The purpose of this test program was to determine the effect of natural gas composition and altitude on regulated emissions and performance of a Cummins B5.9G engine. The engine is a lean-burn, closed loop control, spark ignited, dedicated natural gas engine. For fuel composition testing the engine was operating at approximately 1600 m (5,280 ft) above sea level.

We hypothesize that components designed to improve fuel economy by reducing power requirements should also result in a decrease in emissions of oxides of nitrogen (NOx). Fuel economy and NOx emissions of a pair of class 8 tractor-trailers were measured on a test track to evaluate the effects of single wide tires and trailer aerodynamic devices. Fuel economy was measured using a modified version of SAE test procedure J1321. NOx emissions were measured using a portable emissions monitoring system (PEMS). Fuel consumption was estimated by a carbon balance on PEMS output and correlated to fuel meter measurements. Tests were conducted using drive cycles simulating highway operations at 55 mph and 65 mph and suburban stop-and-go traffic. The tests showed a negative correlation (significant at p < 0.05) between fuel economy and NOx emissions. Single wide tires and trailer aerodynamic devices resulted in increased fuel economy and decreased NOx emissions relative to the baseline tests.

Fracture split forged steel connecting rods are utilized in many new high performance automotive engines to increase durability. Higher strength levels are needed as the power density increases. Fracture splitting without plastic deformation is necessary for manufacturability. Metallurgical design is a key for achieving the required performance levels. Several medium carbon steels containing 0.07 wt pct P, 0.06 wt pct S and various amounts of Mn, Si, V, and N were produced by vacuum induction melting laboratory heats and hot working the cast ingots into plates. The plates were cooled at varying rates to simulate typical cooling methods after forging. Microstructures were generally ferrite and pearlite as evaluated by light optical and scanning electron microscopy. Mechanical properties were determined by standard tensile tests, high strain rate notched tensile tests, and Charpy V-notch impact tests to assess “splittability”.