Your diesel car may still be non-compliant before the age of 10, in that case! – times of India

A recent study led by Rajeev Kumar MishraDiesel cars start emitting hazardous pollutants before the age of 10 currently prescribed in the capital city, suggests an assistant professor in the Department of Environmental Engineering at Delhi Technological University. While age is a factor, diesel vehicle mileage also matters and can render a vehicle unfit before it reaches its scrapping age. The study was published in Springer’s journal Environmental Science and Pollution Research.

The research study was conducted on 460 diesel cars registered at various RTOs in the capital city. It was found that, after the age of 7.5 years or after driving 95,000 km, the cars could not conform to the BS-IV emission norms. The same cars after the age of 9 years or driving more than 1,25,000 km will become BS-III non-compliant. Owners not complying with BS-III norms will not be allowed to obtain pollution certification before the scrapping age of 10 years prescribed for their vehicles. While the estimated age for a BS-III violation is close to the benchmark of 10 years, the prospect of a BS-IV violation at just 7.5 years can be a cause for concern.

The research also found that periodic maintenance plays a major role in how quickly a diesel vehicle does not conform to BS-IV emission norms. Delhi currently has 9 lakh diesel cars plying on the roads and the BS-IV cutoff is strict, allowing only 50 HSUs (Heartridge Smoke Units) to be emitted per vehicle. It used to be 65 HSU units under BS-III norms. While the BS-III type engine car fleet comprises only 5 to 8 per cent of the total diesel car population in Delhi, the results still make a strong case for revising the scrapping policy based on the mileage of a car.

But what about private cars that are well maintained? according to co-researcher Abhinav Pandey, Diesel cars that were older and offered higher mileage were found to meet both BS-IV and BS-III norms. Maintenance factors include vehicle engine tuning, regular servicing, proper maintenance of emission control systems such as catalytic converters and diesel particulate filters that trap gaseous pollutants and PM 2.5 and PM 10 particulates from diesel engines.