A new study of on-road emissions has shown that adding one diesel SUV to the road can cause as much nitrogen oxide pollution as 25 to 65 petrol-based cars, the Centre for Science and Environment (CSE) has noted.
Citing the study titled ‘Laboratory and On-Road Emission Testing of In-use Passenger Vehicles in India’, which was carried out by India-based International Centre for Automotive Technology and US-based International Council on Clean Transportation (ICCT), CSE executive director Anumita Roychowdhury said the ‘dieselgate’ controversy in Europe had been confirmed.
The dieselgate scandal in 2015 had revealed that cars were made to adhere to emission standards when tested in labs, but not when in use on the road. In fact, the ICCT was responsible for unearthing the practice by Volkswagen.
“Diesel cars, particularly large diesel SUVs, are much more polluting than petrol cars. With BS-VI, controlling on-road emissions from diesel vehicles will be more complex and expensive than petrol vehicles,” said Ms. Roychowdhury.
She added that this would amount to “emissions cheating” and that India should have stricter testing and monitoring mechanisms as Europe has done.
According to the study, lab tests showed that nitrogen oxide emissions from on-road diesel cars were higher than BS-IV standards, whereas they were below the standard for petrol cars.
When the same cars were tested on the road, the diesel cars were found to have nitrogen oxide emissions over three to six times the standards as well as nine to 12 times of the petrol variants of the same car. In the case of SUVs, the study found that the real-world nitrogen oxide was four to six times over the standard, which as per Ms. Roychowdhury is “already weak”.