Your diesel car could become non-compliant even before the age of 10 for scrapping, here’s how!

A recent study conducted by Rajeev Kumar Mishra, assistant professor for the Department of Environmental Engineering at Delhi University of Technology, suggests that diesel cars begin emitting dangerous pollutants long before the 10-year scrapping age currently set in the capital. Although age is a factor, the mileage of a diesel vehicle is also important and can make a vehicle unsuitable even before its demolition age is complete. The study was published in Springer’s journal Environmental Science and Pollution Research.

The research study was conducted on 460 diesel cars, registered in various RTOs in the capital. It was found that, after 7.5 years of age or after driving 95,000 km, the cars became non-compliant with BS-IV emission standards. The same cars after 9 years of age or traveling over 1.25,000 km would become non-BS-III compliant. Failure to comply with BS-III standards would also not allow owners to obtain pollution certification for their vehicles before the prescribed 10-year demolition age. Although the predictive age for BS-III violation is close to the 10-year benchmark, the possibility of a BS-IV violation at only 7.5 years could be cause for concern.

The research also found that periodic maintenance plays an important role in how a diesel vehicle soon becomes non-compliant with BS-IV emission standards. Delhi currently has 9 lakhs of diesel cars circulating on its roads and the BS-IV limit is strict, allowing for the issuance of only 50 HSUs (Hartridge Smoke Units) per vehicle. According to BS-III, these were 65 HSU units. Although the BS-III type motor car fleet comprises only 5 to 8% of the total diesel car population in Delhi, the results continue to be a valid argument for revising the mileage-based scrapping policy of a ‘car.

But what about well-maintained private cars? Second co-researcher Abhinav Pandey, those diesel cars that were older and had driven more kilometers were found to comply with BS-IV and BS-III standards. Maintenance factors include tune-up of a vehicle’s engine, regular maintenance, proper maintenance of emission control systems such as catalytic converters and diesel particulate filters that trap gaseous pollutants and PM 2.5 and PM10 particulates emitted by diesel engines.