Oil marketing companies have cut the prices of petrol by 2 rupees 42 a litre and diesel by 2 rupees 25 paise per litre. New rates came into effect midnight last night. In Delhi, petrol will now cost 58 rupees 91 paise a litre, the lowest in 44 months. Similarly, diesel will cost 48 rupees 26 paise a litre in Delhi, the lowest since April 2013.The reduction would have been almost double but for the government also raising excise duty by 2 rupees per litre on both petrol and diesel yesterday. This is the fourth hike in excise duty since November. The four excise duty hikes will result in about 20,000 crore rupees in additional revenue this fiscal and will help the government meet its fiscal deficit target of 4.1% of the GDP.