The International Council on Clean Transportation (ICCT) has unveiled concerning discrepancies between laboratory-tested emissions and real-world pollution levels from vehicles operating in Delhi and Gurgaon. Despite compliance with the Bharat Stage VI (BS VI) emission norms, vehicles in these cities are reportedly emitting pollutants well above regulatory limits during everyday use.
The ICCT’s study, which utilised advanced remote sensing technology to monitor emissions from 110,000 vehicles at 20 locations, highlights a significant gap between type-approval emissions in controlled environments and the actual emissions encountered on the road. This study scrutinised pollutants including carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter (PM) from a range of vehicles. Findings reveal that commercial vehicles, particularly those operating under BS VI norms, produce substantially higher levels of NOx compared to their private counterparts. For instance, BS VI CNG taxis and light goods vehicles were found to emit 2.4 and 5 times more NOx, respectively, compared to private petrol, diesel, and CNG vehicles. This data challenges the prevailing notion of CNG as a clean alternative fuel, showing real-world NOx emissions from BS VI CNG vehicles are significantly above type-approval limits.
The study underscores a critical shortfall in the current Pollution Under Control (PUC) certificates, which do not effectively capture key pollutants like NOx and PM or assess emissions under real-world operating conditions. It advocates for the adoption of remote sensing technology, as seen in Kolkata, to better monitor on-road emissions and identify high-polluting vehicles.
ICCT’s India Managing Director, emphasised the need to overhaul emissions testing regimes and accelerate the transition to zero-emission vehicles (ZEVs). Bhatt stated, “Our data highlights that real-world emissions, rather than laboratory results, impact air quality. This underscores the urgent need for more accurate emissions testing and a push towards cleaner technologies.”
The report also calls for the finalisation and implementation of the Automotive Industry Standard (AIS) 170, which would standardise technical parameters for remote sensing devices and enhance regulatory oversight. Deputy Director of the FIA Foundation, reinforced the study’s implications, noting that CNG is not as clean as previously thought. Officials from the Centre for Science and Environment supports the study’s call for remote sensing, arguing that it could help identify and mitigate the worst emitters and guide future technology and fuel transitions. He added, “While CNG vehicles initially reduced particulate emissions, the high NOx emissions signal the need for a significant shift towards electrification to achieve true zero emissions.”
