The Central Government has approved the use of E100 fuel, which contains 100 per cent ethanol, in vehicles equipped with flex-fuel technology. The Ministry of Road Transport and Highways has amended the Central Motor Vehicles Rules, 1989, through a notification, paving the way for vehicles specifically designed to run on nearly pure ethanol.
 

According to the government’s gazette notification, E100 has been added alongside E85 in the applicable vehicle emission standards. The revised rules specify that these fuels can be used only in vehicles manufactured and designed as flex-fuel vehicles by their respective manufacturers.
 

E85 and E100 Added to Emission Rules
 

E100 consists of 100 per cent ethanol, while E85 contains 85 per cent ethanol. Flex-fuel vehicles are engineered to operate on petrol and ethanol blends in varying proportions.
 

Under the amendments, several provisions of Rule 115, which deals with vehicle emission standards, have been revised to replace references to E85 with the wording “E85 or E100”. The changes establish a regulatory framework for the use of both fuel types in compatible vehicles.
 

The government has also increased the vehicle gross weight limit under the relevant emission standards from 3,000 kg to 3,500 kg.
 

Move Aims to Reduce Dependence on Petrol
 

The amendments are part of India’s broader efforts to increase ethanol use in the transport sector and reduce dependence on conventional petrol. However, the approval does not mean that E100 can be used in every petrol-powered vehicle. Only vehicles specifically designed and approved for compatible flex-fuel operation can use the fuel.
 

The changes follow draft rules issued on April 27, 2026, when the ministry invited objections and suggestions from the public and relevant stakeholders. According to the ministry, the government considered the feedback received before finalising the amendments.
 

The notification states that the revised rules will come into force from the date of their publication in the Official Gazette. However, no timeline has been announced for the widespread commercial availability of E100 fuel across India.
 

What Is Ethanol Fuel?
 

Ethanol is an alcohol-based fuel primarily produced by fermenting sugars or starches obtained from crops such as sugarcane and maize, as well as other plant materials. It can be blended with petrol to reduce the proportion of conventional fuel used in vehicles.
 

E20 petrol contains up to 20 per cent ethanol, while E85 contains 85 per cent and E100 consists entirely of ethanol.
 

Increasing ethanol consumption is intended to help reduce petrol demand and India’s dependence on imported crude oil. Greater ethanol production could also create additional demand for agricultural produce and potentially benefit farmers.
 

However, ethanol production also raises environmental and economic considerations, including the use of water, agricultural land and crops.
 

Can Existing Petrol Cars Use E100?
 

Vehicle owners should note that E100 is not suitable for every petrol car. Engines and fuel systems must be specifically designed to handle high-ethanol blends. Flex-fuel vehicles are developed to operate on petrol and ethanol mixtures in different proportions.
 

Owners of existing petrol vehicles should therefore check their vehicle manufacturer’s guidance and confirm compatibility before using E85 or E100. Using a fuel for which a vehicle has not been designed or approved could cause problems with its engine or fuel system.
 

Higher ethanol content can also mean less energy per litre of fuel, potentially affecting fuel efficiency in some vehicles.
 

Although the government has now amended the rules to permit E100 use in compatible flex-fuel vehicles, the nationwide commercial availability of the fuel remains uncertain, with no official rollout timeline announced so far.