MoRTH notifies E100 flex-fuel rules: existing cars need no change

By Rahul Goyal · 26 Oct, 2026

MoRTH has amended the Central Motor Vehicles Rules to recognise E100 alongside E85 for certified flex-fuel vehicles. Existing petrol and E20 cars are not cleared to use these blends.

MoRTH notifies E100 flex-fuel rules: existing cars need no change

The Ministry of Road Transport and Highways (MoRTH) has notified amendments to the Central Motor Vehicles Rules, 1989, that expressly recognise E100 alongside E85 in provisions covering flex-fuel vehicle emissions and testing. For most Indian car owners, the immediate message is unchanged: an ordinary petrol or E20-compatible car is not authorised to use E85 or E100, and no existing vehicle needs conversion under this notification.

Key takeaways

MoRTH has added E100 alongside E85 in the Central Motor Vehicles Rules framework for eligible flex-fuel vehicles.
E85 and E100 are intended only for vehicles specifically designed and certified by the manufacturer for those blends.
Compatibility with E10 or E20 alone does not establish that a vehicle can use E85 or E100.
The notification does not require owners of existing petrol vehicles to switch fuel or modify their cars.
The next practical questions are which vehicles receive certification and where compatible high-ethanol fuel becomes available.

Image note: This is an AI-generated illustrative editorial image showing a generic pump and compatibility sticker, not an official vehicle or fuel-station photograph.

What MoRTH changed

MoRTH notified the Central Motor Vehicles (Amendment) Rules, 2026, through Gazette notification G.S.R. 911(E), dated 23 Oct 2026 and published in the Official Gazette on 26 Oct 2026. The amendment updates Rule 115 and related emission, fuel-specification and testing provisions so E100 appears alongside E85 for the relevant flex-fuel vehicle categories.

The Ministry said the amended vehicles must meet the emission and safety requirements applicable to their category. It also said the notification updates biodiesel-related provisions and makes technical corrections. The rules take effect from the date of their publication in the Official Gazette, according to the ministry’s 26 Oct release.

E85, E100 and E20 are not interchangeable labels

E85 is a petrol-and-ethanol blend containing up to 85% ethanol by volume. The “E” refers to ethanol and the number indicates its proportion in the fuel. E100 is described by MoRTH as fuel consisting predominantly of ethanol. E20, by contrast, is petrol blended with 20% ethanol and is already the reference point for many vehicles in the current market.

The important distinction is not the name printed at a pump but the vehicle’s certified fuel range. The revised framework says E85 or E100 is for vehicles designed by original equipment manufacturers as flex-fuel vehicles. That creates a compliance route for manufacturers developing higher-ethanol vehicles; it does not turn every petrol vehicle into a flex-fuel vehicle.

What changes for existing car owners

For a conventional petrol car, the notification does not create a new refuelling instruction. MoRTH specifically says that compatibility with E10 or E20 alone does not establish suitability for E85. It also says the change does not require owners of vehicles already in use to switch to E85 or E100 or modify their vehicles, either now or in the future.

That clarification matters because the legal recognition of E100 could otherwise be read as a blanket permission at fuel stations. It is not. A car owner should treat the compatibility sticker on the vehicle and the manufacturer’s owner manual as the controlling references. If those materials do not identify the vehicle as compatible with a particular higher-ethanol blend, the new rule does not supply that approval.

Drivers can continue to use the live fuel-prices page to check the petrol, diesel and CNG rates relevant to their city. The new notification does not itself announce a nationwide retail price or availability schedule for E85 or E100.

What the rule means for buyers and automakers

For automakers, the amendment removes an important regulatory ambiguity: a manufacturer designing a flex-fuel vehicle for higher ethanol blends now has an express rulebook covering the relevant emission certification and testing references. That is a regulatory pathway, not a promise that a new model will launch immediately. A future vehicle would still need the applicable certification, fuel-system design and safety compliance before sale.

For a buyer considering such a vehicle, the useful comparison will extend beyond the showroom price. The certified fuel range, the fuels actually sold on the intended routes, expected consumption, service requirements and warranty wording will all affect the ownership calculation. Those are separate questions from whether E100 is now recognised in the rules.

Why fuel cost still needs a trip calculation

A higher-ethanol fuel rule does not by itself tell a driver what a commute or highway journey will cost. The answer depends on the vehicle’s approved blend, the local pump price, the distance, traffic and the vehicle’s actual consumption. A certified flex-fuel car may offer more choice, but the practical value depends on having compatible fuel where the vehicle is used.

For a route-specific estimate, the fuel cost calculator can combine distance, consumption and the applicable local rate. For a longer journey, the road-trip planner can help organise the route before a driver assumes that a particular fuel will be available along it.

What to check now

Read the fuel-compatibility sticker and owner manual for the exact vehicle and variant.
Do not infer E85 or E100 approval from ordinary petrol, E10 or E20 compatibility.
For a new flex-fuel model, check the manufacturer’s certified blend range and the fuel guidance supplied with the vehicle.
Separate vehicle approval from pump availability: the rule change does not confirm that every retail outlet will stock high-ethanol fuel.

What to watch next

The next developments will be manufacturer announcements, certification of specific flex-fuel models and clearer information on where higher-ethanol fuels can be purchased. MoRTH’s release frames the change as support for wider use of domestically produced ethanol and reduced dependence on imported crude, but the benefit for an individual driver will depend on vehicle compatibility, route availability and real running cost.

For now, the safe takeaway is narrow and useful: E100 has a recognised place in the rules for specially designed flex-fuel vehicles, while existing petrol and E20-compatible cars should continue to follow their own manufacturer-approved fuel instructions.