Today is a good day to shop around if you are filling up the tank after BP put their fuel prices up, a motorists' lobby group says.
Automobile Association general manager Mike Noon said BP put their prices up last night but others have not yet followed, so motorists driving long distance should check the prices before pulling into the petrol station.
BP raised their pump prices by four cents and diesel by three cents while Caltex and Shell have remained the same. The prices come after after another rise of four cents last Friday.
Oil prices topped US$100 ($126) a barrel yesterday, a rise of nearly 5 per cent.
"Some of the prices have gone up but not all of them and I guess the question is, why have the prices gone up? That's a question for the oil companies to answer," Mr Noon said.
He said rushing out to save four cents a litre ahead of a possible price increase is not necessary but if you have the option, it is worth checking the prices.
BP spokeswoman Greta Shirley said the price increases have come on the back of refined fuel price increases of 7.7 per cent since the beginning of February.
In the same period, pump prices have increased by 2.3 per cent, she said.
When asked why other companies had not followed suit in increasing prices, Ms Shirley declined to comment.
Petrol industry minnow Gull have just raised their diesel prices this morning and are now in line with the three other major players after holding out since the last rise.
New Zealand general manager Dave Bodger said the company is watching the price of petrol and will be making a decision "at some stage".
Shell spokeswoman Jackie Maitland said "market intelligence" had told them that BP had risen overnight.
She said the company was reviewing its prices but she could not say when a decision was due to be made.
Caltex spokeswoman Sharon Buckland said the company was holding at the moment and could reconsider around lunchtime.
Mobil have so far not returned phone calls.