An in situ exploratory analysis of diesel cars' emission: way forward on policy evaluation

Keeping in view the significant number of diesel-driven passenger cars in the existing light motor vehicle fleet in Delhi, India, a case study on smoke emission measurement from 460 number of such cars was conducted. Smoke exhaust data was collected from the diesel cars while the vehicles presented themselves for periodic renewal of pollution under control (PUC) certification at authorized emission testing centers across Delhi, India. Along with the smoke emission, various vehicle- and engine-related aspects, supposed to affect tailpipe smoke emission, were also recorded aiming at data analysis for two datasets, namely whole and top 5 makes. The smoke density under no-loading condition in the free acceleration test mode was measured. The study reported a strong correlation between vehicle parameters, such as age, mileage, maintenance category, emission norm, and engine aspiration; and the smoke emission (R