Motorists yesterday won their first fuel price cut since February after jostling by oil companies ended with a reduction of 4c a litre for petrol and diesel.
However, Caltex warned the price reduction may not last.
Shell began the day by lopping 3c off what had been record prices sinceApril. It was followed by Caltex before BP leap-frogged them with a 4c reduction.
Shell, Caltex and Mobil soon matched BP, setting prices at $1.669 at litre for 91-octane petrol, $1.719 for 95-octane, and $1.239 for diesel.
The reduction followed eight weeks of stability at the pumps, although Caltex spokeswoman Sharon Buckland said the companies had ridden out volatile movements in the price of imported refined fuel.
She questioned Shell's decision to trigger a price cut, saying refined petrol was hardly any cheaper now than in April, when retail 91-octane reached $1.709 after successive rises since February, and she could not guarantee prices would stay down.
"There is no evidence it is sustainable," she said of yesterday's price cut.
Shell spokeswoman Jackie Maitland said her company decided to move first after being satisfied a degree of stability had returned to its cost structure. Her counterpart at BP, Diana Stretch, said it had been at least 2 1/2 years since the retail price had stayed unchanged for so long, although she confirmed that international refined product costs had been "up and down" for the past eight weeks.
She acknowledged that summer holidays starting next month in North America might signal more volatility by putting more demand pressure on supplies, and said geopolitical tensions remained around several oil-producing countries such as Iran.
At the end of last year 91-octane fuel cost $1.359 a litre.
