The Ministry of Road Transport and Highways has proposed amendments to vehicle emission rules to enable flex-fuel and pure biofuel vehicles across all vehicle categories. The ministry has proposed amendments to the Central Motor Vehicles Rules, 1989, aimed at providing wider use of fuels, such as E85 (a blend of 85% ethanol with petrol) and E100 (which would allow vehicles to run on nearly pure ethanol), as well as B100 biodiesel and hydrogen-CNG combinations. India has already achieved 20% blending of ethanol (produced from biomass like sugarcane, corn or rice) with petrol to create a cleaner-burning fuel, reducing reliance on imported crude oil and cutting carbon emissions.

Among key proposals, the draft raises the vehicle weight limit from 3,000 kg to 3,500 kg, bringing regulation in sync with global standards for light commercial vehicles. This will lead to more vans, pickups, and small trucks falling under the same emission testing rules. It recognises fuels with higher blends of renewable biofuels - E20 (20% ethanol blended petrol), E85 (85% ethanol), E100 (100% ethanol) and B100 (100% biodiesel). Until now, the rules mostly spoke about E10 and E20. This amendment opens the regulatory door for flex-fuel vehicles and pure biofuel vehicles across all vehicle categories - two-wheelers, three-wheelers, passenger cars, and heavy vehicles.

The Ministry noted that the changes would be taken up after a 30-day public consultation period, during which stakeholders can submit objections or suggestions. Meanwhile, it has updated fuel definitions and standards, including replacing references to ‘Hydrogen+CN’ with ‘Hydrogen+CNG’. It corrected specific emission intensity metric measuring the mass of pollutant (in milligrams) emitted per unit of energy produced to ‘mg/kWh’ from earlier ‘Mg/kWh’. Further, the World-Harmonised not-to-exceed (WNTE) emission limit has been corrected from ‘60’ to ‘600’. WNTE is a global methodology that limits heavy-duty engine emissions during real-world, in-use operation, rather than just in a laboratory. It sets a maximum permissible level for NOx and PM emissions across a broad range of engine speeds, loads, and ambient temperatures.