Ethanol-blended petrol hits consumers with lower mileage despite higher fuel costs

• By Thetripurapost Desk, New Delhi
• Sep 01, 2025
• 562

Consumers are facing a double burden as both automobile manufacturers and the government admit that ethanol-blended petrol (E20) can reduce vehicle mileage by 2%–6%, even as fuel prices remain high.

Take the case of Surender Pal Singh, a Delhi-based automobile engineer and former principal of a vehicle driving institute. Singh said his car’s mileage has dropped noticeably over the last few months.

“When I bought it, my car gave me around 17–17.5 km per litre on Delhi roads. Last year, it slipped to 16.5 km, which I thought might be due to my driving habits or traffic conditions. But in the past 4–5 months, the mileage has touched 14.5 km,” Singh said. He added that after switching to premium fuel—around ₹7 costlier per litre—he saw some improvement in mileage.

Several other motorists have echoed similar experiences on social media, questioning why they are being forced to pay more for fuel that delivers less efficiency.

A 2021 Niti Aayog report on the “Roadmap for Ethanol Blending in India 2020-25” had warned of such concerns, recommending that ethanol-blended fuel be sold at a lower retail price than regular petrol to offset the drop in calorific value. It also suggested tax breaks on ethanol to make the switch more attractive.

The report highlighted expected mileage drops with E20:

6%–7% loss for four-wheelers designed for 100% petrol (E0) but calibrated for E10

3%–4% loss for two-wheelers designed for E0 and calibrated for E10

1%–2% loss for four-wheelers designed for E10 and calibrated for E20

It also noted that with proper modifications to engine hardware and tuning, efficiency losses could be reduced.

Meanwhile, the Automotive Research Association of India (ARAI) maintains that its 2016 and 2021 studies did not find any adverse impact of E20 on vehicles.