New Delhi [India], December 28 (ANI): Union Minister for Road Transport and Highways Nitin Gadkari has said that to substitute import of petroleum as fuel and provide direct benefits to farmers, the automobile manufacturers in India have now been advised to start manufacturing Flex-Fuel Vehicles (FFV) and Flex-Fuel Strong Hybrid Electric Vehicles (FFV-SHEV) complying with BS-6 norms in a time-bound manner within a period of six months.