its time (rather late) to mix ethanol in petrol and diesel to fit pocket of the mango ppl. Mr Pranab mukherjee and team has been reportedly doin something in this regard but noting came out in 3 months. see - Ethanol-blended petrol: GoM to look into issues: Rediff.com Business . it has got some disadvantages - higher ethanol concentration damages rubber parts (hoses, seals etc) and if spilled while filling.. even the body paint of cars. but by the use of FFV (flexible fuel vehicles)(costly affair though) which are resistant to any kind of damage due to ethanol, this can be achieved and emissions will also reduce ! i think 10-25 % can be mixed w/o any significant problems faced !!