Research Projects

Project at a Glance

Project Status: complete

Title: Testing for exhaust emissions of diesel powered off-road engines.

Principal Investigator / Author(s): Mridul Gautam Ph.D

Contractor: West Virginia University

Contract Number: 98-317

Research Program Area: Emissions Monitoring & Control

Topic Areas: Mobile Sources & Fuels


Emissions databases from off-road diesel powered equipment suffer immensely from insufficient real-world activity data. Moreover, there is little information available regarding the validity of standardized dynamometer engine test cycles that are currently used for emissions certification. The present study was initiated in order to fill the current void in the off-road equipment testing cycles and the consequent lack of "real world" emissions data that is needed for accurately modeling emissions inventories.

For this study, onboard engine data was logged from four off-road vehicles in order to generate transient test cycles that could be used to simulate real-world operating conditions for exhaust emissions research. The off-road diesel powered equipment targeted for this study was selected to be representative of the major off-road diesel emissions contributions in California. Specifically, these vehicles were: an Elgin Pelican street sweeper (51-120 hp), a John Deere 444 rubber-tired loader (121-250 hp), a Komatsu PC400LC3 excavator (251-500 hp), and a Caterpillar D-11RCD bulldozer ( > 500 hp). The engines were removed from the street sweeper, rubber-tired front-end loader, and the excavator and operated according to the transient test cycles developed from the recorded in-field data, as well as the standard steady-state 8-mode test cycle, prescribed by ISO 8178-6.3 Test Cycles type C, which is used for certification of off-road diesel engines. Regulated gaseous emissions and gravimetric PM emissions were collected according to procedures recommended by the Code of Federal Regulations (CFR) 40, Part 86, Subpart N. In addition, size-selective PM mass emissions, and particle sizing data were collected. Exhaust emissions from the Caterpillar D-11R CD track-type tractor were measured in the field as the dozer performed its normal operating activities. This on-board testing was performed using West Virginia University's mobile Emissions Measurement System (MEMS) for gaseous exhaust components, and a Real time Particulate Mass Monitor (RPM 100) developed by the Mid-Atlantic Research Institute (MARI).

Results indicate that the current steady-state, ISO 8178, 8-mode test cycle does not adequately represent the actual emissions produced by off-road, diesel-powered equipment during day-to-day operations. Furthermore, the exhaust emissions produced by a vehicle are highly vehicle and task-specific.


For questions regarding research reports, contact: Heather Choi at (916) 322-3893

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