India Amends Vehicle Rules for E85 and E100 Flex-Fuel Vehicles

On 23 October 2026, the Ministry of Road Transport and Highways (MoRTH) amended the Central Motor Vehicles Rules, 1989. The amendments were published in the Official Gazette on 26 October 2026 and came into immediate effect. They permit specially designed and certified flex-fuel vehicles to use E85 and E100 fuels.

Emission Rules and Certification

The amendments include E100 alongside E85 in relevant provisions, including Rule 115 and Rule 115E, which cover vehicle emission standards and testing requirements. E85 is a fuel blend containing up to 85% ethanol, while E100 refers to fuel containing nearly 100% ethanol. The rules restrict the use of these fuels to vehicles designed and certified by original equipment manufacturers (OEMs) as flex-fuel vehicles. Conventional petrol vehicles, including vehicles compatible with E10 or E20, cannot use E85 or E100 unless they receive appropriate certification or modification.

Vehicle Compatibility and Fuel Classifications

The notification does not require owners of existing vehicles to switch to E85 or E100 or to modify their vehicles. Compatibility with lower ethanol blends, such as E10 or E20, does not by itself establish that a vehicle can safely use higher ethanol blends. The amendments also update fuel classifications, including replacing an earlier E10 reference with E20 in a relevant provision and revising provisions concerning biodiesel. They change the gross vehicle weight threshold specified in certain emission standards from 3,000 kg to 3,500 kg.

Ethanol Blends and Flex-Fuel Technology

Ethanol is an alcohol used as a transport fuel and blended with petrol in different proportions. The “E” designation in fuel labels refers to ethanol, and the accompanying number denotes its percentage in the blend; for example, E20 contains 20% ethanol. Flex-fuel technology enables a suitably designed vehicle to operate on petrol and ethanol blends in varying proportions. Onboard sensors detect the fuel mixture and allow the engine control system to adjust engine parameters. The government has stated that the regulatory changes are intended to support the use of domestically produced ethanol and reduce dependence on imported crude oil.

Important Facts for Exams

• E20 denotes petrol blended with 20% ethanol.
• E85 can contain up to 85% ethanol, while E100 denotes near-pure ethanol fuel.
• Rule 115 and Rule 115E of the Central Motor Vehicles Rules, 1989, concern vehicle emission standards and testing provisions.
• Only vehicles designed and certified for flex-fuel operation are authorised to use E85 and E100 under the amended provisions.

The amended rules do not make E85 or E100 use compulsory for existing vehicle owners. The revised gross vehicle weight threshold in certain emission standards is 3,500 kg.