This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
I/M Short Tests and Cutpoints for 1981 and Newer Emission Control Technology
Annotation ability available
Sector:
Language:
English
Abstract
Manufacturers have used a number of alternative emission control technologies to meet the emission standards for 1981 and later model years. Each technology type can have malperformances that lead to high emissions, but the ability of inspection/maintenance short tests to identify high emitters varies considerably by technology. In this study, the relationships between malperformance types, FTP emissions and short test emissions were identified for several major technology types, using data from the EPA Emission Factor data base. Based on these relationships, methods to enhance the effectiveness of I/M tests are suggested. The analysis indicated that the most important factor governing the ability of any I/M short test is the presence of absence of secondary air. The short tests were found to be incapable of recognizing any malperformance except severe misfire if secondary air was present. Without secondary air, the short tests could identify many common malperformances leading to high emissions.
Recommended Content
Authors
Topic
Citation
Duleep, K., Wang, D., and Crawford, R., "I/M Short Tests and Cutpoints for 1981 and Newer Emission Control Technology," SAE Technical Paper 851185, 1985, https://doi.org/10.4271/851185.Also In
References
- Duleep, K.G. “Future Automotive Emission Control Technology and Strategy,” SAE Paper No. 841244 October 1984
- Lorang, P.A. White, J.T. Brzezinksi, D.J. “In-Use Emissions of 1980 and 1981 Passenger Cars: Results of EPA Testing,” SAE Paper No. 820975 February 1982
- Energy and Environmental Analysis, Inc. “Investigations Relating to In-use Emissions of 1980 and Later Vehicles,” report to the EPA under EPA Contract No. 68-01-6558 September 1984