After six cuts in past eight days, petrol and diesel prices were reduced across four metros Delhi, Kolkata, Mumbai and Chennai on Thursday (February 15). While the decrease in petrol rates was of magnitude 15-16 paise per litre across the four cities, diesel rates were lowered by 90-96 paise per litre. Effective 6 am, February 15, 2018, petrol rates were at Rs. 72.79 per litre in Delhi, Rs. 75.49 per litre in Kolkata, Rs. 80.66 per litre in Mumbai and Rs. 75.49 per litre in Chennai, according to Indian Oil Corporation's website - iocl.com. Diesel rates were at Rs. 63.32 per litre in Delhi, Rs. 65.98 per litre in Kolkata, Rs. 67.43 per litre in Mumbai and Rs. 66.77 per litre in Chennai, according to Indian Oil. Petrol (Rs. per litre) 15-Feb 14-Feb 7-Feb 31-Dec 1-Jun-17 Delhi 72.79 72.94 73.38 69.97 66.91 Kolkata 75.49 75.64 76.07 72.72 69.52 Mumbai 80.66 80.81 81.24 77.87 78.44 Chennai 75.49 75.65 76.12 72.53 69.93 Diesel (Rs. per litre) Delhi 63.32 63.5 64.22 59.64 55.94 Kolkata 65.98 66.17 66.89 62.3 58.28 Mumbai 67.43 67.62 68.39 63.27 61.67 Chennai 66.77 66.96 67.73 62.83 59.22 (Source: iocl.com) Here are 10 things to know on petrol and diesel rates on February 15: 1. Since February 7, petrol rates have been lowered by a cumulative 58-63 paise per litre including Thursday's cut. Diesel rates have been cut by 90-96 paise per litre during this period. 2. On February 7, petrol retailed at Rs. 73.38 per litre in Delhi, Rs. 76.07 per litre in Kolkata, Rs. 81.24 per litre in Mumbai and Rs. 76.12 per litre in Chennai. Diesel retailed at Rs. 64.22 per litre, Rs. 66.89 per litre, Rs. 68.39 per litre and Rs. 67.73 per litre, respectively. 3. Since then, oil marketing companies have cut petrol and diesel rates in the four metros every day except February 14. 4. So far this year, petrol rates were up by Rs. 2.82 per litre in Delhi, Rs. 2.77 per litre in Kolkata, Rs. 2.79 per litre in Mumbai and Rs. 2.96 per litre in Chennai. Diesel rates were up by Rs. 3.68 per litre in Delhi, Rs. 3.68 per litre in Kolkata, Rs. 4.16 per litre in Mumbai and Rs. 3.94 per litre in Chennai. 5. Petrol and diesel rates are revised with effect from 6 am every day. 6. Petrol and diesel retailers in the country - with Indian Oil Corporation being the largest - adopted a daily price revision system in June last year. 7. Since June 1, 2017, petrol rates were up by Rs. 2.22-5.97 per litre in Delhi, Kolkata, Mumbai and Chennai. Diesel rates are up by Rs. 5.76-7.70 per litre in the four metros. 8. In the current scheme of petrol and diesel price revision, the prices of the two fuels are determined broadly by the global crude oil rates and the rupee-dollar exchange rate. 9. The recent turmoil in global financial markets has hit crude prices. OPEC and its partners, including Russia, have curbed supply since January 2017 to drain global stocks in an agreement that continues through the end of the year. 10. Crude has also benefited from the dollar's weakness. Oil tends to move inversely to the dollar, and has also of late been trading in tandem with stocks.