India Approves E100 Ethanol Fuel for Flex-Fuel Vehicles: What the New Rules Mean

The Ministry of Road Transport and Highways today notified changes to the Central Motor Vehicles Rules (CMVR), allowing flex-fuel vehicles that can run on up to E100 ethanol fuel. The notification comes months before some carmakers are expected to launch their E100 models.

E85 and E100 are meant only for vehicles that are designed and certified to run on the high ethanol blend fuels, and cars running on E20 or normal petrol can't use them. The new notification will not force owners of existing vehicles to switch to these high ethanol blended fuels as these would require modifications of their vehicles due to the corrosive nature and density differences of E100 compared to our current fuels.

Union Minister of Petroleum and Natural Gas Hardeep Singh Puri fills a car with E100 - Image Source: PTI

What The New Amendment Changes in the CMVR

The new E100 notification from the Government , G.S.R. 911(E), dated October 23, 2026 and published today amends Rule 115 of the CMVR, 1989, replacing references to E85 with E85 or E100 across the applicable vehicle emission and testing provisions.

MoRTH has also changed vehicle classification thresholds, fuel specifications and technical references used in emission-related tables and testing provisions. The weight limit for light petrol and diesel vehicles covered by these changes has been raised to 3,500 kg from 3,000 kg.

The draft rules for these changes were published on April 27, 2026, and opened for public consultation. The draft was aimed at wider use of E85 and E100, B100 biodiesel and hydrogen-CNG combinations across vehicle categories. However it is to be noted that this final amendment is just a regulatory approval for E100 capable vehicles and does not establish nationwide retail availability of E100 ethanol fuel like it did for E20.

E100 - How Does It Differ From E20 & E85

Unlike the E20 fuel sold in India today, which contains 20% Ethanol and 80% petrol, E100 is nearly pure ethanol with no petrol component, while E85 features 85% ethanol and 15% petrol. Flex-fuel vehicles can run on a range of ethanol and petrol blends from a single tank, using engineered fuel systems, compatible materials and different engine-management calibrations. Depending on the vehicle's design and certification, the usable range may extend to E85 or E100. Not every vehicle sold as flex-fuel supports the full range from E20 to E100, so buyers need to check the manufacturer's fuel approval.

Existing petrol cars cannot be filled with pure ethanol. Vehicles built for petrol or E20 lack the components and calibration for high-ethanol blended fuel operation, including fuel-system components, cold starting and fuel delivery. Only vehicles designed from the ground up and certified for the fuel can use E100 ethanol fuel. Running a regular petrol or E20-compatible car on E100 risks both performance problems and causing damage to various components of the powertrain.

Why India Wants Higher Ethanol Blends - What It Means for You & Carmakers

India imports much of its crude oil, one of the biggest contributors to its current account deficit. India currently produces ethanol domestically for blended fuels from sugarcane-based feedstocks, maize and other permitted agricultural raw materials, which have helped the government reduce the amount of petroleum imported for use by road transport.

The push for higher blended fuel with higher Ethanol content has become a major talking point thanks to the ongoing West Asia conflict between the alliance of the US and Israel on one side and Iran and its proxies on the other. This conflict has not just raised oil prices to triple digits (Brent crude is currently trading at $114.80 per barrel)but has also left several countries, India included, vulnerable to an energy crisis thanks to the constant blockades and counter blockades.

To counter this major vulnerability, India has turned towards Ethanol blended fuel and last year saw a nationwide adoption of E20 fuel, many years ahead of schedule. However, the government's heavy handed implementation of E20 has resulted in quite a bit of backlash from the public, many of whom still do not have E20 compatible vehicles.

And while the switch towards E20 has opened up a larger ethanol ecosystem farmers, distilleries and allied industries. Ethanol also has a lower fossil carbon footprint than conventional petrol, and higher blends reduce tailpipe emissions of carbon monoxide and certain hydrocarbons. However, the overall production and usage of ethanol for fuel still depends on feedstock cultivation, manufacturing energy and transport usage as well as the efficiency of your vehicle, so switching to E100 will not automatically mean zero emissions.

Ethanol also has a lower energy content per litre than petrol. A vehicle running on E100 generally needs more litres to cover the same distance, with the gap depending on engine design and calibration. A lower price per litre for E100 may offset that, however, it will not guarantee a lower running cost per kilometre. Competitive pump prices and engines engineered for ethanol will ultimately decide how E100 compares with regular petrol and E20 .

Carmakers have already jumped into the flex fuel game or are working on vehicles that can run on these higher ehtnaol blended fuels. Maruti Suzuki launched the Wagon R Flex Fuel in June 2026 and the hatchback is India's first flex-fuel passenger vehicle, capable of running on blends from E20 to E85. Toyota Motor Corporation, Tata Motors and Hyundai Motor Company are also developing flex-fuel vehicles for the Indian market.