India has taken another step towards expanding the use of high-ethanol fuels in road transport, with the Ministry of Road Transport and Highways (MoRTH) amending the Central Motor Vehicles Rules, 1989.
The changes formally bring E100 alongside E85 in emission certification provisions, giving vehicle manufacturers a clearer regulatory framework for developing and certifying flex-fuel vehicles capable of using higher ethanol blends. The amended rules came into effect from the date of their publication in the Official Gazette.
What are E85 and E100 fuels?
E85 is a petrol-ethanol blend containing up to 85% ethanol by volume. The “E” refers to ethanol, while the number indicates the approximate ethanol content in the fuel. E100, meanwhile, refers to fuel consisting predominantly of ethanol.
Unlike conventional petrol vehicles, flex-fuel vehicles are engineered to operate on different petrol-ethanol blends through a single fuel system.
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Depending on the vehicle’s design and certification, a flex-fuel vehicle may be capable of running on blends ranging from lower ethanol concentrations to E85 or E100.
The technology is already established in Brazil. Flex-fuel vehicles use fuel-system components designed for approved ethanol concentrations, while engine-management systems can adjust the vehicle’s operation according to the fuel being used.
What does the new MoRTH rule change mean?
The key change is the formal inclusion of E100 in the regulatory framework for flex-fuel vehicles. The amended provisions update emission certification and testing requirements so that vehicles certified for E85 and E100 must comply with the applicable emission and safety standards for their respective categories.
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This gives automakers a defined regulatory route to develop and eventually commercialise vehicles designed to run on very high ethanol blends, including E100.
The move follows earlier regulatory provisions that had already recognised E85 and E100 for flex-fuel vehicles. The latest amendment further updates the certification framework and incorporates E100 into relevant emission provisions.
E20 cars cannot simply switch to E85 or E100
One of the most important clarifications from the government is that E85 and E100 are not fuels for ordinary petrol cars. A vehicle designed and certified for E10 or E20 should not be assumed to be compatible with E85 or E100. High-ethanol fuels require vehicles with fuel-system components, materials and engine controls specifically designed and certified for those blends.
The government has therefore made it clear that the new rules do not require owners of existing vehicles to switch to E85 or E100 or modify their vehicles. For motorists, the advice remains straightforward: check the fuel compatibility sticker on the vehicle and follow the manufacturer’s instructions in the owner’s manual before choosing a fuel at a filling station.
Why is India promoting high-ethanol fuels?
The push towards ethanol is closely linked to India’s efforts to reduce its dependence on imported crude oil. Greater use of domestically produced ethanol can help reduce the amount of petrol required from fossil-fuel sources. It can also create additional demand for domestically produced biofuel.
There may be environmental benefits as well. Ethanol use in appropriately designed vehicles can reduce certain exhaust pollutants and may lower greenhouse gas emissions across the fuel’s lifecycle. However, the overall emissions impact depends on factors such as the feedstock used and how the ethanol is produced.
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India has also been expanding the availability of high-ethanol fuel. In June 2026, E85 was launched at 48 retail outlets operated by public-sector oil marketing companies, specifically for compatible flex-fuel vehicles.
What should existing vehicle owners do?
For most current petrol vehicle owners, nothing changes because of this notification. The amendment does not mean that conventional petrol vehicles must start using E85 or E100. It also does not require owners to retrofit their existing cars for high-ethanol fuels.
In fact, using a fuel for which a vehicle has not been designed and certified could create compatibility and performance issues. Drivers should therefore rely on the manufacturer’s fuel compatibility information rather than assuming that a vehicle capable of using E20 can also use E85 or E100.
Flex-fuel vehicles could get a clearer path to market
The regulatory change is significant for automakers because it establishes clearer certification provisions for vehicles designed around high ethanol concentrations. For consumers, however, the availability of compatible vehicles and fuels will determine how quickly the technology becomes mainstream.
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The government is positioning ethanol as part of a broader strategy to strengthen energy security, reduce crude oil import dependence and expand the use of domestically produced fuels.
Biodiesel rules are also updated
The latest notification is not limited to ethanol. MoRTH has also made changes to biodiesel-related provisions and introduced technical corrections to the Central Motor Vehicles Rules.
Indrani Priyadarshini is a journalist and editorial professional specialising in technology, artificial intelligence, smart cities, green energy, and digital transformation. With over four years of experience in tech journalism and digital media, she is known for turning complex industry developments into clear, engaging, and insightful stories. Her expertise spans reporting, editorial strategy, digital publishing workflows, and in-depth coverage of emerging technologies shaping the future.
