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Governments and regulatory agencies in North America are evaluating the nitrogen oxides (NOx) emissions of heavy-duty on-road vehicles to effectively regulate these emissions in order to improve public health and meet air quality requirements. This paper provides results from real-world Class 8 tractor-trailer truck activity and emissions data gathering conducted in the Northeast and Mid-Atlantic United States. Unlike some other areas of the United States (US), there is little available data on in-use operation and emissions performance from heavy-duty trucks in this region where temperatures can be consistently cold in winter.

This paper presents the fuel consumption results of engine and vehicle simulation modeling for a wide variety of individual technologies and technology packages applied to a long haul heavy duty vehicle. Based on the simulation modeling, up to 11% in fuel savings is possible using commercially available and emerging technologies applied to a 15L DD15 engine alone. The predicted fuel savings are up to 17% in a Kenworth T700 tractor-trailer unit equipped with a range of vehicle technologies, but using the baseline DD15 diesel engine. A combination of the most aggressive engine and vehicle technologies can provide savings of up to 29%, averaged over a range of drive cycles. Over 30% fuel savings were found with the most aggressive combination on a simulated long haul duty cycle. Note that not all of these technologies may prove to be cost-effective. The fuel savings benefits for individual technologies vary widely depending on the drive cycles and payload.

Medium- and Heavy Duty Truck fuel consumption and the resulting greenhouse gas (GHG) emissions are significant contributors to overall U.S. GHG emissions. Forecasts of medium- and heavy-duty vehicle activity and fuel use predict increased use of freight transport will result in greatly increased GHG emissions in the coming decades. As a result, the National Highway Traffic Administration (NHTSA) and the United States Environmental Protection Agency (EPA) finalized a regulation requiring reductions in medium and heavy truck fuel consumption and GHGs beginning in 2014. The agencies are now proposing new regulations that will extend into the next decade, requiring additional fuel consumption and GHG emissions reductions. To support the development of future regulations, a research project was sponsored by NHTSA to look at technologies that could be used for compliance with future regulations.

This paper presents the results of engine and vehicle simulation modeling for a wide variety of individual technologies and technology packages applied to two medium-duty vocational vehicles. Simulation modeling was first conducted on one diesel and two gasoline medium-duty engines. Engine technologies were then applied to the baseline engines. The resulting fuel consumption maps were run over a range of vehicle duty cycles and payloads in the vehicle simulation model. Results were reported for both individual engine technologies and combinations or packages of technologies. Two vehicles, a Kenworth T270 box delivery truck and a Ford F-650 tow truck were evaluated. Once the baseline vehicle models were developed, vehicle technologies were added. As with the medium-duty engines, vehicle simulation results were reported for both individual technologies and for combinations. Vehicle technologies were evaluated only with the baseline 2019 diesel medium-duty engine.

This paper presents the results of an in-use emissions testing program which investigated the emissions and duty cycles from five heavy-duty construction vehicles. The program examined the emission reduction potential of various retrofit control technologies including; diesel oxidation catalysts, passive particulate filter, and active particulate filter technologies. Analysis of the results are provided for both the original vehicle configuration and with the vehicles retrofitted with exhaust aftertreatment systems. The vehicles studied included a dump truck, two wheeled loaders, a backhoe and a bulldozer. The paper will discuss in-use heavy-duty vehicle emissions and the use of emissions control technologies.