Petrol will be dearer by Rs. 1.63 per litre excluding VAT from midnight on Friday. This is the seventh increase since June.An Indian Oil Corporation statement issued in New Delhi said average International prices of petrol has gone up to 117.40 dollar per barrel from 114.44 dollar per barrel and depreciation of the rupee against the dollar led to the hike. As per the new rates, petrol will cost Rs. 76.06 per litre in Delhi, Rs. 83.63 in Kolkata, Rs. 83.62 in Mumbai and Rs. 79.55 in Chennai.