Your diesel car may be unfit even before it hits scrapping age, study shows

Over 460 cars, registered at various regional transport offices across the city, were monitored and it was found that after around 7.5 years of age or 95,000km of run, these cars become non-compliant with BS-IV emission norms. Usually, it would take nearly nine years or 1,25,000km mileage for them to become BS-III non-compliant.

In both cases, the recertification of pollution under control certificates should not be allowed for such cars, the study pointed out.

Vehicular emissions in Delhi are a major cause of pollution in the city which is known for its hazardous Air Quality Index (AQI).

The study, led by Rajeev Kumar Mishra, assistant professor of the environmental engineering department at Delhi Technological University, was based on various factors like the inclusion of mileage, age as well as the condition of a diesel car to phase it out.

“Although the predictive age of nine years in case of BS-III standard is close to the maximum allowable registration period of 10 years in Delhi, the 7.5 years of predictive age for the BS-IV cutoff is a concern, given the fact that the impending tighter emission norms of BS-VI may let the in-use vehicles become non-compliant even faster,” TOI quoted Mishra as saying.

“Currently, BS-IV is stricter because it allows only 50 HSU (Hartridge smoke units), while BS-III allows up to 65 units. The units allowed under the BS-VI norms are still awaited,” said co-researcher Abhinav Pandey.

Pandey called the situation alarming as maximum cars on the capital’s road are BS-IV-type. He said that all diesel cars, if not maintained, would become non-compliant with both BS-IV and III norms before the current scrapping age in Delhi.

About 5-8% of the total fleet of diesel cars in Delhi are BS-III-type, Pandey pointed out. The BS-VI compliant engines started to roll out after April 1, 2020. “What we suggest is not to phase out a car merely on its age, but also the mileage. Thus, the scrapping policy needs to be relooked into,” he emphasised.

Pandey, however, added that a better-maintained car, even if its older and had clocked more mileage, was found to be compliant with both BS-IV and BS-III norms.

(With inputs from TOI)