Published : 27 October 2026
Read Time : 5 min
Author: Nikil Jonathan
The Ministry of Road Transport and Highways (MoRTH) have amended the Central Motor Vehicles Rules (CMVR), 1989, to formally recognise E100 fuel for compatible flex-fuel vehicles. The change creates a clearer regulatory pathway for automakers to develop and certify vehicles that can run on higher ethanol blends, including fuel containing 100% ethanol. However, it does not mean that existing petrol cars can use E100 or that the fuel will become available at every petrol pump immediately.

For car owners, the key takeaway is simple: if your car is designed for conventional petrol or E20, you do not need to make any changes because of this notification. E85 and E100 are intended for vehicles specifically designed and approved for these fuels.
The letters and numbers in these fuel names indicate the proportion of ethanol in the fuel. Ethanol is an alcohol-based fuel that can be produced from feedstocks such as sugarcane and maize.
E10 and E20 contain a mixture of petrol and ethanol. E85 contains 85% ethanol and 15% petrol, while E100 is pure ethanol fuel. Vehicle compatibility depends on the manufacturer’s design and certification, rather than simply on whether a car has a petrol engine.
The government has amended Rule 115 of the Central Motor Vehicles Rules, 1989, which covers vehicle emission standards and related testing requirements.
Previously, several relevant provisions referred to E85. The amendment replaces those references with E85 or E100, bringing E100 explicitly into the applicable regulatory framework. It also adds a clear note stating that E85 or E100 must be used in vehicles designed by original equipment manufacturers (OEMs) as flex-fuel vehicles, such as the Maruti WagonR Flex Fuel
Also Read: Maruti Suzuki WagonR Flex Fuel Launched At Rs. 7.24 Lakh
The main development for passenger-car buyers is the formal recognition of E100 alongside E85. This is a regulatory change, not an announcement that all petrol cars can use high-ethanol fuel. Automakers will still need to develop vehicles that meet the applicable technical, emission and safety requirements.
No, not unless the manufacturer has specifically designed and approved the vehicle for the relevant fuel. Most conventional petrol cars are engineered for the fuel blends specified by their manufacturers. A vehicle approved for E20 is not automatically compatible with E85 or E100.
Higher ethanol concentrations require appropriate fuel system materials, components and engine management calibration. Using an unapproved fuel can cause starting or running problems and may damage components. Even if a vehicle is marketed as a flex-fuel model, buyers must check which ethanol blends it is approved to use.
For example:
No. The notification does not require existing petrol car owners to modify their vehicles, switch fuels or replace their cars. The government has not announced a requirement for existing petrol cars to convert to flex-fuel technology.
If you currently own an E20-compatible petrol car, continue following the fuel recommendations in the owner’s manual. Do not use E85 or E100 unless the manufacturer explicitly approves the fuel for your vehicle.
If you are considering buying a future flex-fuel car, check the manufacturer’s stated compatibility range. The vehicle’s documentation and fuel-compatibility markings should identify the approved ethanol blends.
Not immediately. The notification recognises E100 within the vehicle regulatory framework, but it does not announce nationwide availability or a rollout schedule for E100 fuel.
For the technology to become practical for everyday buyers, three things need to come together:
Ethanol also contains less energy per litre than petrol. As a result, a vehicle running on E100 will generally consume more litres to cover the same distance than it would on petrol, although the actual difference depends on the engine and vehicle design. It’s worth noting that a lower price per litre, if offered, would not automatically guarantee lower running costs per kilometre.
India’s ethanol programme is intended, in part, to reduce dependence on imported crude oil by increasing the use of domestically produced alternative fuels.
Ethanol can be produced using agricultural feedstocks, creating opportunities for domestic producers and associated industries. Higher ethanol use may also reduce lifecycle greenhouse gas emissions under suitable production conditions, although the overall environmental impact depends on how the fuel is produced and transported.
The latest amendment supports this broader direction by giving automakers a clearer regulatory route to certify vehicles for higher ethanol blends. However, it does not establish how quickly E100 vehicles will reach showrooms or how widely the fuel will be sold.
Yes. MoRTH have amended the Central Motor Vehicles Rules to recognise E100 alongside E85 in the relevant provisions for compatible vehicles.
No. E20 compatibility does not automatically mean a vehicle can run on E100. The manufacturer must specifically approve the vehicle for that fuel.
E100 is 100% ethanol fuel, while E85 contains 85% ethanol and 15% petrol.
No. The amendment does not require existing petrol cars to be modified or converted to flex-fuel technology.
No such nationwide rollout has been announced in the notification. Availability will depend on the development of the retail fuel infrastructure.
No. The amendment does not announce the discontinuation of E20 petrol or a nationwide switch to E100. The two fuel categories can serve different vehicles according to their approved fuel compatibility.
Also Read: Pros And Cons Of Flex Fuel Vehicles (Ethanol Blend)
Before you finalise your next car, these V3Cars tools can help you make a more informed decision:
Did you find this information helpful?

Content Writer
Nikil's a huge fan of classic cars, especially Italian beauties such as the Alfa Romeo Giulia Sprint and the Iso Grifo. His love for cars and bikes originated when he first laid his eyes on a poster of the Ferrari F40 and the MV Agusta F4 when he was just a child. He also loves all things analogue, especially vintage cameras and turntables.

























Comments
0 comments