Emission standards development for an I/M program

This paper presents the results of vehicle exhaust measurements that were used to establish emission standards for an I/M program. For this purpose, a total number of 100 private autos distributed across model years ranging between 1972 and 2002 were tested under idling conditions. The monitored indicators included air to fuel ratio (%), CO (%), CO2 (%), HC (ppm), NOx (ppm) and O2 (%). Private autos with model years greater than 1994 were found to be compliant with international standards and are relatively well maintained. Emissions from older models increased significantly with lack of engine maintenance. The paper concludes with criteria for proposing I/M emission standards based on exhaust measurements taking country-specific socio-economic characteristics into consideration

Emission standards development for an inspection/maintenance program

This paper presents the results of vehicle exhaust measurements that were used to establish emission standards for an inspection/maintenance (I/M) program. For this purpose, a total number of 100 private autos distributed across model years ranging between 1972 and 2002 were tested under idling conditions. The monitored indicators included air to fuel ratio (%), CO (%), CO2 (%), HC (parts per million, ppm), NOx (ppm), and O2 (%). Private autos with model years greater than 1994 were found to be compliant with international standards and are relatively well maintained. Emissions from older models increased significantly with a lack of engine maintenance. The paper concludes with criteria for proposing I/M emission standards based on exhaust measurements taking country-specific socioeconomic characteristics into consideration