Petrol prices were on Friday hiked by Rs 1.63 per litre, the seventh increase since June, on rising oil rates and falling rupee.
The increase excludes local sales tax or VAT and will be effective midnight tonight, oil firms said.
The petrol price in Delhi will go up by Rs 1.96 to Rs 76.06 per litre, while it will cost Rs 83.63 per litre in Mumbai as against Rs 81.57 currently.
With this increase, petrol prices have gone up by a massive Rs 10.80 per litre since June, excluding VAT.
The price in Delhi has surged by Rs 13.06 per litre, inclusive of state tax, since June 1.
A cut in petrol prices had been expected on September 15/16, the scheduled date for fortnightly revisions, on the back of an appreciating rupee over the past few days.
However, the oil firms advanced the date and announced the increase after factoring in the rupee's depreciation in the early part of the month.
Indian Oil Corp, the nation's largest oil firm, said average international prices of petrol have gone up to US $117.40 a barrel from US $114.44 a barrel while the average exchange rate has deteriorated to Rs 66.02 a dollar in September from Rs 63.88 a dollar in the second half of August.
"To give effect to these twin reasons, the Corporation is required to increase petrol prices by Rs 1.63 (excluding VAT) with effect from midnight of September 13-14," it said.
The appreciation in the rupee during the past one week "will be passed on to consumers in the next fortnight," IOC said.
Oil firms had raised petrol prices by 75 paise, excluding VAT, on June 1 and followed it with increases of Rs 2 per litre on June 16, Rs 1.82 on June 29, Rs 1.55 on July 15, 70 paise on August 1 and Rs 2.35 on September 1.
Diesel prices may soon see a one-time hike of Rs 3-5 per litre, kerosene of Rs 2 a litre and LPG of Rs 50 per cylinder as the Oil Ministry looks at ways to tackle a record Rs 180,000 crore of losses from the dipping rupee and surging oil rates.
IOC said the deteriorating exchange rate had led to losses on diesel widening to Rs 14.50 per litre from Rs 12.12 in the second half of August.
The oil firms are also losing Rs 36.83 per litre on kerosene and Rs 470.50 per cylinder on LPG.
"Should the recent trend of stabilisation and appreciation of rupee-USD exchange rate continue and international petrol prices also not move adversely, the beneficial effect of the same will be passed on to the consumers in the next fortnight," it said.
Diesel currently costs Rs 51.97 a litre in Delhi and LPG Rs 410.50 a cylinder in the capital.
At current rates, IOC expects to end the fiscal with a revenue loss of about Rs 82,000 crore on selling diesel, LPG and kerosene.
The industry (IOC, Bharat Petroleum Corp and Hindustan Petroleum Corp) estimates a total revenue loss of Rs 156,000 crore.
"The movement of prices in the international oil market and rupee-USD exchange rate are continuously under watch and developing trends reflected in future price changes," the statement added.