E20 Ethanol-Blended Petrol: Effect on Engine and Mileage of Vehicles? Govt Responds to Social Media Buzz

Many vehicle owners had expressed concern about the potential hazards to ethanol-blended petrol engines. Using ethanol-blended fuel in older cars can not only negatively affect mileage but can also shorten engine life and increase repair costs. The central government has started selling ethanol-blended petrol in India to protect the environment and save money on crude oil imports. Initially, 10 per cent ethanol was mixed, which has now been increased to 20 per cent. However, this has resulted in engine damage, leading to an increase in vehicle damage and maintenance. As a result, drivers are beginning to feel that cars that have to be driven on ethanol are a bit of a bargain. The central government has now clarified the drivers' concerns.

📑Some articles/ reports in the media have raised concerns about the potential negative impact of 20% ethanol blending (E20) in petrol, particularly with regard to older vehicles and customer experience. These concerns, however, are largely unfounded and not supported by…

— Ministry of Petroleum and Natural Gas #MoPNG (@PetroleumMin) August 4, 2025

Many vehicle owners had raised concerns about the potential dangers to ethanol-blended petrol engines. Using ethanol-blended fuel in older cars can not only negatively affect mileage but can also shorten engine life and increase repair costs.

The Ministry of Petroleum and Natural Gas has issued an explanation on X after seeing the issue flare up. "It is not true that blending ethanol with petrol is causing damage to vehicles or causing unnecessary inconvenience to consumers," the ministry said. Ethanol blending is a visionary, scientifically supported and environmentally responsible solution.

Also Read | E20 Petrol does not cause drastic drop in fuel efficiency, even improves engine performance: Petroleum Ministry.

"Some articles/ reports in the media have raised concerns about the potential negative impact of 20% ethanol blending (E20) in petrol, particularly with regard to older vehicles and customer experience. These concerns, however, are largely unfounded and not supported by scientific evidence or expert analysis," said MoPNG.

The first 100,000 km of carbonated and fuel-injected vehicles have been monitored. Inspections conducted every 10,000 km internationally showed no negative effects on power, torque or mileage. Tests conducted by the Automotive Research Association of India (ARAI), Indian Institute of Petroleum (IIP) and Indian Oil Corporation (R&D) have also not found any problems in older vehicles on E20 fuel, the ministry said.

"International studies on the effect of using Ethanol-Petrol Blends on Mechanical, Energy and Environmental Performance of Vehicles through testing of carbureted and fuel-injected vehicles every 10,000 km during their first 100,000 km showed statistically no significant differences in power and torque generated and fuel consumption," said the ministry in a post on X.

The ministry has agreed to people's claims that ethanol-blend fuel reduces mileage. Ethanol has a lower energy density than regular gasoline, which leads to a slight reduction in mileage. This could be a decline of about 1-2% for four-wheelers designed for the E10 and calibrated for the E20 and about 3-6% for other vehicles. The ministry said the reduction could be mitigated slightly if engine tuning is done well and E20-compliant components are used.

The ministry also clarified on the claim that the use of ethanol damages the engine system, carburettor or fuel injector of the vehicle and leads to expensive repairs. "E20 fuels are well verified by BIS guidelines and automotive industry standards. However, after a long use of about 20,000 to 30,000 km in some older vehicles, it may be recommended to replace some rubber parts/gaskets. It is cheap to replace and can be easily done during regular servicing of the vehicle," the ministry said.

Overall, it is not very wrong for consumers to say that ethanol petrol is affecting old cars or bikes. However, this percentage is not very large, according to the ministry. Maintenance that comes at a few longer intervals may come a little sooner. The ministry says mileage could be affected by 4-5 per cent.