A 2021 NITI Aayog roadmap has resurfaced, showing that automakers supported India’s ethanol-blending plan but also urged the government to continue selling E10 petrol alongside E20.
The Society of Indian Automobile Manufacturers (SIAM) said E10 should remain available as a “protection grade” fuel for older vehicles. It warned that many existing vehicles were not designed for higher ethanol blends and could face compatibility, fuel-efficiency, and drivability issues.
SIAM also said retrofitting millions of older vehicles for E20 would be difficult and impractical. The industry body cautioned that using E20 in incompatible vehicles could lead to fuel system wear, leakage risks, and reduced performance, especially in low-powered two-wheelers.
The report noted that E20 may reduce fuel efficiency by up to 6% because ethanol has lower energy content than petrol. However, studies by ARAI, Indian Oil, and the Indian Institute of Petroleum found no major engine damage or abnormal wear during testing.
The government has recently dismissed claims that E20 causes widespread engine failures, stating that the fuel was introduced only after extensive testing.
The roadmap ultimately supported a phased shift to E20 while recommending that E10 remain available during the transition to protect the existing vehicle fleet.