The other oil companies have all followed Caltex's move to raise pump prices here. ExxonMobil, Singapore Petroleum Co and Shell on Wednesday upped petrol prices by three cents a litre and diesel by five cents.

Their increases, within hours of each other, came a day after Caltex revised prices upwards. With the changes, a litre of 92, 95 and 98-octane petrol is $2.083, $2.116 and $2.190 before discount, while diesel is $1.663. Shell's V-Power is $2.309, while Caltex's Platinum is $2.316.

The latest pump price adjustment is the 10th consecutive increase since July last year - 11th if the GST-triggered increase on July 1, 2007 were to be included. Singapore's goods & services tax was raised from 5 to 7 per cent last July.

The relentless increase in pump prices is just one of several price spirals Singapore residents are facing. The country's inflation rate, at 6.7 per cent in March, is at the highest level in almost three decades. Some analysts are predicting it would reach 7 per cent this year, fuelled by high food and oil prices.

Likewise, crude oil prices are trading at record levels. In New York trading on Tuesday, oil hit US$119.90 (S$160) as the American currency weakened against the euro. This prompted investors to pick up more commodities - including oil - as an inflation hedge.

Some observers have questioned why pump prices here are not softening on the back of the strengthening Singapore dollar. The local currency is trading at an all-time high of $1.35 per US dollar.

Meanwhile, the escalation in fuel prices is costing motorists dearly. Drivers will now incur nearly $1,000 more in fuel a year than in January 2007, when a litre of petrol was $1.50. Station discounts, at 19 per cent back then, have dwindled to 5 per cent.