India’s transition towards petrol blended with 20% ethanol by volume (E20) is an important part of its broader effort to diversify transport fuels, support domestic agriculture and reduce reliance on imported crude oil. The policy can provide national-level benefits, but it also raises practical questions for individual motorists. Ethanol has a lower energy content per litre than petrol, so some vehicles may record a modest reduction in kilometres travelled per litre. Vehicle compatibility, maintenance requirements, retail prices, agricultural supply chains and the availability of clear consumer information therefore matter to the overall outcome. This paper examines E20 from the perspectives of household expenditure, vehicle performance, the environment, energy security, consumer rights and public policy. A worked example illustrates how a 4% mileage reduction could affect a commuter’s budget; it is an illustration rather than a guarantee of the result for every vehicle. The paper concludes that the success of E20 should be assessed through transparent data, vehicle-specific guidance, fair warranty practices and careful monitoring of both benefits and costs.