No damage, but 3-5% lower mileage: Govt admits E20 impact on pre-2023 vehicles

Amid concerns over ethanol blending in petrol, the government on Monday acknowledged a marginal reduction in fuel economy in pre-2023 E10-compatible vehicles.

Replying to a question in the Rajya Sabha, Minister of State for Petroleum and Natural Gas Suresh Gopi said, “Any reduction in fuel economy in certain E10-designed vehicles is generally marginal (around 3–5%).”

He added that mileage depends far more on driving habits, tyre pressure, servicing and AC load than on fuel type.

“Government, automobile manufacturers and vehicle testing agencies have clarified that fuel efficiency depends on several factors, including driving habits, vehicle maintenance, tyre pressure, wheel alignment and air-conditioning load,” he said.

On E20 fuel, the ministry said it contributes to cleaner and more efficient engine operation, improves emissions performance, and is compatible with fuel systems and materials. It does not cause abnormal wear and tear or compatibility issues, the ministry said.

Citing manufacturer service data, Gopi said one leading four-wheeler manufacturer serviced 2.84 crore vehicles during FY 2025–26, including 1.5 crore older, non-E20-certified vehicles, without reporting any vehicle damage attributable to E20 fuel.

“Similarly, one of the leading two-wheeler manufacturers reported that analysis of extensive service data found no higher incidence of damage in vehicles operating on E20 compared with earlier fuel blends. Manufacturers continue to honour warranty obligations for vehicles using specification-compliant fuel,” he added.

The government has been seeking to allay customer concerns over the impact of E20 on vehicle fuel economy.

“At present, no decision has been taken by the Government to increase ethanol blending in petrol beyond 20% or to introduce ethanol blending in diesel for commercial use,” he said.

The government recently issued a draft notification proposing amendments to the Central Motor Vehicles Rules to formally incorporate higher blends of ethanol in petrol.