Why is take up of bio-fuel slow in sugar-producer India?
6 October 2013 Last updated at 08:55 BST
The Indian government has decreed that petrol should be diluted with 5% ethanol, in a bid to reduce its oil import bills.
The idea seems straightforward as ethanol is made from sugar cane and India has plenty.
However, three months after the new rules came into force, little has changed.
Shilpa Kannan reports from Tamil Nadu - one of India's key ethanol producing areas.