The Central Government has approved the use of E100 fuel, containing approximately 100% ethanol, in certified flex-fuel vehicles in India by amending the Central Motor Vehicles Rules (CMVR), 1989.

The Ministry of Road Transport and Highways (MoRTH) issued the notification, G.S.R. 911(E), on October 23, 2026. The amended rules came into effect upon publication in the Official Gazette. The development was widely reported around October 26.

What Has Changed Under the New Rules?

The government has amended Rule 115, which deals with vehicle emission standards, and related provisions to include E100 alongside E85 fuel.

According to the explanatory note, E85 and E100 can be used only in vehicles specifically designed and certified as flex-fuel vehicles by original equipment manufacturers (OEMs).

These vehicles are designed to operate on petrol and different ethanol blends, including E100, depending on their certified fuel compatibility.

No Changes Required for Existing Petrol Vehicles

The new approval does not apply to existing petrol vehicles or vehicles certified only for E10 or E20 fuel.

The ministry has clarified that compatibility with E10 or E20 does not automatically mean a vehicle can safely operate on E85 or E100.

Existing vehicle owners are not required to switch fuels or make any modifications to their vehicles following the amendment.

Motorists should continue to follow the fuel compatibility sticker displayed on their vehicle and the instructions provided in the owner's manual.

Regulatory Path Cleared for E100 Flex-Fuel Vehicles

The amendment establishes a regulatory framework for the commercial production and homologation of flex-fuel vehicles capable of operating on ethanol blends up to E100.

Some automobile manufacturers had already been developing flex-fuel models. Maruti Suzuki, for example, launched the Wagon R Flex Fuel in June 2026, designed to operate on ethanol blends ranging from E20 to E100.

By updating the motor vehicle rules, the government has formally recognised the use of E100 in appropriately designed and certified flex-fuel vehicles.

For existing petrol vehicle owners, the key point remains unchanged: only fuels approved by the vehicle manufacturer should be used.