Comparison of In-Use Emissions from Diesel and Natural Gas Trucks and Buses
2000-01-3473
12/04/2000
- Event
- Content
- Emissions from heavy-duty vehicles in real operation on the road often differ greatly from those that would be projected from laboratory testing. Reasons for this difference include variations between laboratory and real-world driving conditions, wear and deterioration that are not effectively modeled by laboratory tests, inadequate or inappropriate in-use maintenance, and the use of “cycle-beating” strategies and “defeat devices” by engine manufacturers. This paper analyzes data showing in-use emissions from heavy-duty diesel and natural gas vehicles tested using various driving cycles on chassis dynamometers. It is shown that average in-use emissions of particulate matter (PM) and oxides of nitrogen (NOx) from late model heavy-duty diesel engines are much higher than predicted by current emission models, and greatly exceed the emission standards to which these engines were certified. In-use PM emissions from heavy-duty natural gas engines are found to be lower than projected from certification data, while in-use NOx emissions from natural gas engines vary by manufacturer.
- Pages
- 8
- Citation
- Weaver, C., Turner, S., Balam-Almanza, M., and Gable, R., "Comparison of In-Use Emissions from Diesel and Natural Gas Trucks and Buses," SAE Technical Paper 2000-01-3473, 2000, https://doi.org/10.4271/2000-01-3473.