In India, the government made 20% ethanol blended petrol, called E20, the default fuel across all fuel stations under its ethanol blending programme. India’s discussion around flex-fuel vehicles echoes parts of Brazil’s pathway, where ethanol moved from blending to direct use in flex-fuel vehicles. However, the comparison of India’s and Brazil’s ethanol transition also shows the difference. Nicola Pamplona has watched Brazil’s ethanol transition for around three decades, both as a journalist and as a vehicle user. A book on Brazil’s ethanol journey, Bioethanol: Fast track to mobility decarbonisation, coordinated, underlines why higher ethanol fuels require vehicle and fuel-system adaptation.