New Delhi: You will have to pay up to 50 paise more for cleaner motor fuels in Delhi, Mumbai, Chennai, Kolkata and nine other major cities that plan switch to Euro-IV grade. Petrol in Delhi will be costlier by 50 paise per litre at Rs 47.93 per litre and diesel by 26 paise at Rs 38.10 a litre. TOI had first reported on March 23 that cleaner fuel will cost more. The hike is aimed at helping state-run companies recover some Rs 40,000 crore they had invested in upgrading their refineries for producing green fuel. Euro-IV standards specify a maximum of 50 parts per million of sulphur in petrol and diesel. This will be third increase in diesel rates for Delhi in less than a month and the second for petrol. Petrol price had gone up by Rs 2.71 and diesel by Rs 2.55 a litre from February 27 as finance minister Pranab Mukherjee hiked duties on the fuels. Diesel price went up by Rs 2.37 on March 23 when the Delhi government raised VAT. Shift to BS III in rest of India postponed to October 1: The government on Wednesday decided to defer the stricter Bharat Stage III emission norms by six months to October 1, apparently due to inability of oil companies to provide compatible fuel across the country. While 13 cities switch over to BS IV norms on Thursday, the rest of the country was to move over to BS III norms from existing BS II. TNN