New meta-analysis urges faster EV adoption, real-world emission tracking, and grid decarbonisation for accurate climate impact assessments

Battery Electric Vehicles (BEVs) in India produce up to 38 per cent lower carbon dioxide equivalent (CO₂e) emissions per kilometre than internal combustion engine (ICE) vehicles in the passenger car segment, according to a new study conducted jointly by the Indian Institute of Technology (IIT) Roorkee and the International Council on Clean Transportation (ICCT).

The research – one of the first meta-analyses of life cycle greenhouse gas (GHG) emissions for passenger vehicles in the country – draws insights from six major assessments to present a unified picture of emission variability and mitigation strategies.

The study identifies grid carbon intensity, laboratory test assumptions, and real-world driving conditions as the three biggest contributors to variability in vehicle emissions. Together, these account for nearly 75 per cent of the range in life cycle GHG emissions observed across vehicle types.

Differences in India’s electricity generation mix and vehicle energy efficiency can result in a staggering emissions variation of up to 368 grams of CO₂e per kilometre—equivalent to the footprint of driving two to three petrol cars per kilometre.

Despite this variability, BEVs consistently outperform both ICE and hybrid electric vehicles (HEVs) across life cycle emissions. The research warns against deferring BEV adoption while waiting for a cleaner grid. ICE vehicles bought today will remain in use for over a decade, continually emitting, whereas BEVs stand to benefit from India’s progressive decarbonisation of its power sector.

“Electric vehicles are more efficient than ICE vehicles and become increasingly cleaner as India’s power grid decarbonises. Delaying the adoption of BEVs risks locking in long-term emissions from ICE vehicles,” said Amit Bhatt, India Managing Director, ICCT.

The study flags a critical mismatch between lab-tested and real-world energy use, particularly in HEVs. Many assessments rely on overly optimistic assumptions, distorting emissions estimates. It calls for the inclusion of real-world correction factors and more transparent data collection, especially for BEVs where charging losses are frequently overlooked.

“India’s road transport decarbonisation pathway toward its net-zero target is incomplete without the accelerated adoption of BEVs,” noted Namita Singh, co-author and ICCT researcher.

Another overlooked variable in many emissions studies is land-use change associated with biofuel production. Depending on whether these emissions are included, diesel production-related emissions can vary from 8 to 22 grams of CO₂/km. The authors advocate for incorporating these impacts to avoid underestimating the environmental cost of biofuels.

Policy recommendations for clean transport

To strengthen India’s clean transport trajectory, the study outlines actionable steps for policymakers:

Accelerate BEV adoption alongside grid decarbonisation
Tighten fuel efficiency standards for all vehicle categories
Mandate On-Board Fuel and Energy Consumption Meters (OBFCMs) for accurate real-time monitoring
Incorporate land-use change emissions into life cycle assessments of biofuels

“What we assume today shapes the climate impact tomorrow,” said Sunitha Anup, ICCT researcher and co-author. “Future life-cycle assessments must reflect real-world conditions and the evolving electricity grid over a vehicle’s lifetime.”

The findings serve as a timely reminder that India’s transition to clean mobility is not just about cleaner fuels or advanced vehicles—but also about the precision and realism of the tools used to measure progress.