Did Ethanol Petrol (E20) Cause a Drop in Car Mileage? Here's the Government's Response

Concerns have been circulating that E20 petrol (petrol blended with 20% ethanol) leads to a significant drop in vehicle mileage and damages fuel tanks and engines. In response, the Ministry of Petroleum and Natural Gas has clarified that while ethanol does have a lower energy density than pure petrol—which means it can marginally reduce fuel efficiency—the impact is minor and within acceptable limits.

Mileage Impact Explained:

• For vehicles originally designed for E10 petrol (10% ethanol) and calibrated for E20, the government notes a possible mileage drop of just 1–2%.

• In other vehicles (not specifically optimised for E20), the reduction in mileage could be around 3–6%.

• This slight reduction can be minimised with improved engine tuning and by using E20-compatible materials—many new vehicles in India have these as standard from April 2023 onwards.

Engine and Fuel System Safety:

• Claims of significant engine or fuel tank damage from E20 are not supported by scientific studies, according to the ministry.

• Minor parts replacements—like rubber seals or gaskets—may be needed in some older vehicles after extended use (generally after 20,000 to 30,000 km), but these are inexpensive and part of regular maintenance.

• For modern and E20-compliant vehicles, there is no evidence of abnormal wear or increased maintenance needs due to ethanol blending.

Additional Benefits and Policy Goals:

• Ethanol blending is part of India’s environmental and economic policy to reduce carbon emissions, support farmers, and decrease dependence on imported crude oil.

• Since the ethanol blend initiative started, India has saved thousands of crores in foreign exchange and reduced carbon emissions significantly.

Summary:

• E20 petrol may cause a marginal drop in mileage, more so for older vehicles not built for ethanol blends, but drastic declines and major mechanical damage are unfounded.

• With ongoing updates in vehicle technology and materials, even this minor impact can be reduced further.

• E20 is considered safe, sustainable, and beneficial both for consumers and the country’s energy and environmental strategies.