Monitoring of In-use Vehicle Emissions in India 981379

The exhaust emission legislation for automotive vehicles came into effect in India from 1991. Since then, the exhaust mass emission certification tests are conducted on a prototype vehicle for emission compliance before commencing commercial production. The exhaust emission norms are reviewed and tightened after every five years. This should lead to a better emission control system in new vehicles. But the old vehicles which are designed prior to emission control era continue to emit heavily due to their inherent design and condition. The problem of in use vehicle emissions will be on the rise with the low scrappage rate of old vehicles in India. The impact of implementing tighter norms for new vehicles on ambient air quality can be felt only after a period of about 10 years. To have an effective improvement in ambient air quality levels, it is necessary to identify the gross polluters and retune them for bringing their emissions to an acceptable level. In this context, an effective I & M program for Indian condition is critical for the improvement of ambient air quality.

An exercise was undertaken at ARAI to conduct trials on vehicles of different vintage in as received condition and after ensuring maintenance as specified by the vehicle manufacturer. The impact of proper maintenance on the in-use vehicle emissions was studied. A total of 34 petrol driven vehicles of different category like Two Wheelers, Three Wheelers and Four Wheelers with different vintages were tried out. Two short tests of Idle emissions and high idle emissions at engine speed of 2500 rev/min were tried out to identify the gross polluters. The correlation between the idle emissions/high idle emissions at engine speed of 2500 rev/min and mass emissions was sought to be established