India, Aug. 21 -- In a first, the government is considering a plan to introduce new-generation vehicles with flex-fuel engines that run on different combinations of diesel and isobutanol, a biofuel derived from ethanol, two people aware of the matter said. The new diesel engines would operate on the same principle as flex-fuel engines that use varying blends of petrol and ethanol and may even be able to run entirely on isobutanol. Several auto companies are expected to launch two-wheelers, three-wheelers and small commercial vehicles based on these flex-fuel engines, which can use one or more fuel types and are said to reduce consumption of fossil fuels and cut carbon emissions. The ministry of road transport and highways has asked the Automotive Research Association of India (ARAI) to study whether vehicles can run on diesel blended with the ethanol derivative. The study will initially test the feasibility of 10% isobutanol-blended diesel, the first person said. Subsequently, ARAI will assess the development of diesel-based flex-fuel engines that can use as much as 100% isobutanol as fuel. The government's plan to use isobutanol comes amid a controversy over the higher blending of ethanol (20%) in petrol (E20) impacting fuel mileage and long-term engine wear, indirectly contributing to higher-than-stated levels of pollution. However, the government has defended the sale of 20% ethanol-blended petrol, saying it cuts emissions and lowers dependency on imported oil. The idea now is to extend the concept of blending to help reduce emissions from a larger number of vehicles in the country that use diesel. Any effort to reduce diesel consumption would also help cut the country's multi-billion-dollar fuel import bill by a higher margin. Consumption of diesel in India stood at over 91 million tonnes in FY25, while that of petrol was about 40 million tonnes, according to data from the ministry of petroleum and natural gas. India paid $137 billion to import 234 million tonnes of crude oil to meet more than 80% of its oil needs. Isobutanol is a biofuel derived from ethanol by fermentation. It has a higher energy density and is less corrosive than ethanol, properties that make it suitable for blending with diesel. The ministry has asked ARAI to study the use of 10% blended fuel in different categories of vehicles that run on diesel. Successful completion of these tests will help the use of isobutanol-blended diesel in existing vehicles. In the second stage, isobutanol will be tested on specially designed diesel engines or flex-fuel engines to see whether various combinations of the ethanol derivative, including 100% isobutanol, can help run vehicles and make India among the first few countries to achieve this feat, the second person said. Once the ARAI reports are available, the ministry will discuss the 10% blending plan with the oil ministry, prepare a roadmap for implementation and seek Cabinet approval, the second person added....