Gadkari said the use of ethanol as vehicle fuel would help save at least Rs 20 per litre despite its lower calorific value compared to petrol. His ministry is likely to announce a policy for flex-fuel engines soon, which will encourage automobile manufacturers to produce them. These engines can run on more than one fuel and also a mixture of fuels.Gadkari said the use of ethanol as vehicle fuel would help save at least Rs 20 per litre despite its lower calorific value compared to petrol. His ministry is likely to announce a policy for flex-fuel engines soon, which will encourage automobile manufacturers to produce them. These engines can run on more than one fuel and also a mixture of fuels.