Project at a Glance

Title: Determination of the effects of speed, temperature, and fuel factors on exhaust emissions.

Principal Investigator / Author(s): Chou, David

Contractor: Automotive Testing and Development Services

Contract Number: 92-323

Research Program Area: Health & Exposure

Topic Areas: Mobile Sources & Fuels, Modeling


This study provided a comprehensive approach to examining the relative significance and possible synergistic effects of speed, temperature and fuel on mobile source emissions modeling. Tests were conducted on each vehicle with a random combination of three fuel types (Phase I, Phase 2 and Indolene), three temperatures (50oF, 75oF and 100oF) and ten-speed cycles. It was found interaction terms among fuel, speed and temperature were statistically insignificant. Individually, the temperature and fuel factor played a minor role in exhaust emission modeling. Speed and vehicle type were the two dominant factors determining exhaust emissions. These results confirmed the assumption in EMFAC that speed, temperature and fuel factors are independent from each other. Staff recommends that more resources should be allocated to cycle related research in future.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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