India may soon mandate blending isobutanol with diesel as part of its efforts to reduce crude oil imports and strengthen energy security, according to V. Umashankar, secretary at the Ministry of Road Transport and Highways (MoRTH). Speaking at a Confederation of Indian Industry (CII) summit in Delhi, Umashankar said the proposal is being taken "very seriously" and could be rolled out later this year.
- India imports more than 85 percent of its crude oil requirements
- Officials see isobutanol as a way to cut crude oil import dependence over time
The proposal represents a significant step in India's search for alternatives to conventional diesel, with policymakers now turning to isobutanol after unsuccessful ethanol-diesel blending trials.
What is isobutanol?
Isobutanol is a higher-energy biofuel made from ethanol
Isobutanol is a biofuel made from ethanol. It contains more energy than ethanol and is less corrosive, making it better suited for blending with diesel. Because it mixes more readily with diesel than ethanol, isobutanol is considered a promising fuel for diesel blending. Preliminary studies suggest it may be used in existing diesel engines with limited modifications, although further testing is underway.
Why is India exploring diesel blending?
The govt sees it as a potential way to reduce dependence on imported crude oil
One of the government’s goals is to reduce dependence on imported crude oil. India imports more than 85 percent of its crude oil requirements, leaving it exposed to global energy price swings and ongoing pressures from the global energy market. As a result, diesel continues to retail at close to Rs 100 per litre in several major cities.
Although the proposed diesel-blending mandate, if implemented this year, is unlikely to bring down current fuel costs, officials believe increased use of domestically produced biofuels such as isobutanol could reduce reliance on imported fossil fuels over time, especially in the heavy transport sector.
Why did the government move away from ethanol-diesel blending
The shift to isobutanol follows unsuccessful ethanol-diesel blending trials. In September 2025, Union Road Transport Minister Nitin Gadkari said, “Experiments were carried out to blend 10 percent ethanol with diesel, but they turned out to be unsuccessful. Now efforts are being made to blend diesel with isobutanol”.
The challenge is that ethanol does not mix easily with diesel. While India has successfully rolled out E20 petrol, diesel needs a different approach. Researchers say isobutanol’s properties make it better suited for diesel blending and may help cut emissions from trucks, buses and other heavy vehicles. If implemented, the proposed mandate would move isobutanol from testing to wider commercial use in diesel blending.
Saptarshi Mondal
Suraj Viswanathan
Uday Singh
Ajit Dalvi
