New Delhi, June 15 -- India's government seems to be going full throttle on the use of ethanol in vehicles. On Saturday, road transport and highways minister Nitin Gadkari said he had approved regulations for the use of E100 fuel, or 100% ethanol, in vehicles. "People used to laugh" at the proposition, he said, but now ethanol could become a "viable alternative to petrol."

The government's aim is to promote the use of alternative fuels so as to reduce Indian imports of crude oil, which is a point of vulnerability for India's economy. With plentiful crops available locally from which ethanol can be made, its deployment as fuel makes sense.

The effort's success, however, will depend on how widely it is adopted by industry and users. Brazi...