All four oil companies - Shell, Caltex, ExxonMobil and Singapore Petroleum Company (SPC) - have increased pump prices for petrol and diesel by five cents.
Shell was the first to raise pump prices at 8am on Wednesday, followed by Caltex at 10am and then ExxonMobil and SPC at 4pm.
In the past 11 months, the price of petrol has shot up nine times and twice just in this month alone.
The price for 98-octane petrol, used mostly in luxury cars, was relatively stable from January to March, at S$1.637 per litre.
But from April, it jumped thrice to reach S$1.84 in July and increased to S$2.03 in early November. It now costs S$2.08 a litre.
The oil companies said they increased pump prices to reflect current market conditions caused by higher crude oil prices.
Various reasons may cause a hike in pump prices such as local market conditions, rising cost of crude oil, forces of supply and demand, competition and government regulation.
The price of crude oil has steadied around US$94 a barrel on Wednesday after hitting record high levels last week.
New York's benchmark contract had climbed close to the historic level of US$100 last week, reaching a peak of US$99.29 on concerns over tight supplies. - CNA/vm