Government notifies E100 flex-fuel vehicle rules; raises weight limit to 3,500 kg for petrol, diesel vehicles

The Ministry of Road Transport and Highways (MoRTH) on Monday notified amendments to the Central Motor Vehicles Rules, allowing for the classification and regulatory recognition of flex-fuel vehicles capable of running on ethanol blends of up to E100, or nearly pure ethanol. The move comes as the government seeks to expand the use of alternative fuels and reduce India’s dependence on imported crude oil.

A senior ministry official clarified that fuels with ethanol content above E20 and up to E100 are intended exclusively for vehicles designed and certified to use them. Conventional vehicles approved for E20 petrol or normal petrol cannot use higher blends such as E85 or E100, underscoring the importance of vehicle compatibility and certification.

The amendments also revise certain vehicle classification thresholds, fuel specifications and technical references in emission-related tables and testing provisions. The government has raised the applicable vehicle weight threshold for light petrol and diesel vehicles covered by the changes to 3,500 kg from 3,000 kg.

E100 push builds on India’s E20 rollout

India has already rolled out E20 petrol, comprising 20% ethanol and 80% petrol, as part of its efforts to diversify fuel sources and reduce its crude oil import bill. Ethanol blending can help lower the consumption of conventional petrol, although the overall impact on oil imports depends on domestic ethanol availability, demand and the economics of production.

Flex-fuel vehicles are designed to operate on a wider range of ethanol-petrol mixtures, including E85, which contains 85% ethanol and 15% petrol, and E100, which is nearly pure ethanol. Such vehicles require appropriate engine technology and fuel-system components to handle higher ethanol concentrations.

Automakers develop flex-fuel models

In June 2026, Maruti Suzuki India launched the Wagon R Flex Fuel, which the company described as India’s first flex-fuel passenger vehicle. The model is designed to run on ethanol-petrol blends ranging from E20 to E100, marking a step towards expanding the availability of vehicles compatible with higher ethanol concentrations.

Other automakers, including Toyota Motor Corporation, Tata Motors and Hyundai Motor Company, are also developing flex-fuel vehicles for the Indian market as policymakers seek to encourage alternative-fuel technologies.

Energy security adds urgency to ethanol transition

The push towards flex-fuel mobility assumes greater significance amid the West Asia conflict and the resulting vulnerability of energy-importing economies to supply disruptions and price volatility. India’s dependence on imported crude oil exposes its economy to movements in global oil prices and can add pressure to its external balances.

Earlier, MoRTH had proposed amendments to vehicle emission rules to widen the scope for higher ethanol blends and alternative fuels. The draft changes to the Central Motor Vehicles Rules, 1989, envisaged provisions for fuels such as E85 and E100, B100 biodiesel and hydrogen-CNG combinations. Monday’s notification marks a further regulatory step towards enabling the use of higher-ethanol fuels in compatible vehicles.