India's chief economic adviser calls for lower-ethanol petrol option

Ethanol contains less energy than petrol. The authors estimated a 6-7% energy penalty from E20, far smaller than the reductions sometimes claimed online. Testing in the United States and India found no evidence of increased engine wear in E20-compatible vehicles.

The opinion piece also questioned whether India should push ethanol blending beyond the E20 target. Higher levels could intensify competition between fuel production and food crops. Maize now accounts for about half of India's ethanol feedstock; grains together make up nearly 67%. Maize competes with oilseeds such as soybean and groundnut for land, complicating efforts to cut edible-oil imports.

Water use is another concern. The authors said policymakers should focus on "blue water" drawn from rivers and groundwater rather than headline estimates that include rainfall. The climate benefit of grain-based ethanol beyond E20 is not clear-cut, they said, since studies differ on emissions from cultivation and processing.

India's ethanol programme has helped clear sugarcane arrears, supported rural incomes and provided a guaranteed market for producers. Holding the blend at E20 carries its own costs, since distillery capacity was built around expectations of rising demand.

"The engine row we witnessed was never the real argument. The real one is about what we choose to grow, and what we will not be able to take back," the opinion piece said.

Nageswaran and Poojari recommended restoring a lower-blend option, adjusting pricing and water-use incentives that favour maize over competing crops, reconsidering edible-oil import duties, and holding at E20 until the food-versus-fuel trade-off has been fully assessed.