Indian Oil Corp (IOC), the nation's biggest oil firm, has begun the supply of the world's cleanest petrol and diesel across the country with all its 28,000 petrol pumps dispensing ultra-low sulphur fuel a good two weeks before the April 1 deadline. "We have successfully rolled out the supply of BS-VI grade fuel across the country," IOC Chairman Sanjiv Singh said. "All our 28,000 petrol pumps across the country are dispensing BS-VI grade fuel for more than a week now." Other fuel retailers, Bharat Petroleum Corp Ltd (BPCL) and Hindustan Petroleum Corp Ltd (HPCL), are also progressively supplying BS-VI grade fuel and the entire country will switch to the cleanest fuel within this week.The government had set April 1 as the deadline for starting supply of Euro-VI emission compliant fuels. With this India joins the select league of nations using petrol and diesel containing just 10 parts per million of sulphur in an attempt to cut vehicular emissions that are said to be one of the reasons for the choking pollution in major cities.