National petrol prices have fallen to $2 a litre for the first time in two and a half years.
BP and Z both claimed to have led the market this morning in reducing their national price for 91-octane petrol to 199.9c.
They have been joined at that price this afternoon by both Mobil and Chevron, which runs to Caltex brand.
But industry minnow Gull is asking what took them so long, saying it reduced its maximum price for 91-octane to that level a fortnight ago.
Gull's lowest price today is 184.9c in Rotorua and three of its stations in Botany, East Tamaki and Otara are selling the grade at 185.9c, says managing director Dave Bodger.
He says Gull's average price across 45 North Island stations under its control is 192.5c.
BP has reduced prices for all its petrol grades by 3c a litre, and for diesel by 2c.
The other oil majors have gone one better by reducing diesel as well as petrol by 3c.
Jonty Mills of BP says the cuts were his company's 10th in a row since early October.
"This is the first time for two and a half years that petrol has been under $2 per litre nationally and we're thrilled to be able to offer this to all our customers across the country," he said.
"We acknowledge that in some highly-competitive hot-spots it has been under $2 for some time but we are a national player and this is a national reduction."
The move was enabled by international supply exceeding demand, reinforced by OPEC deciding against cutting production.
"It's great news leading into the festive season," Mr Mills said.
"We've passed on these benefits as quickly as possible and now the whole country can enjoy cheaper fuel."
Z spokeswoman Christine Langdon said her company had led a 3c cut in national main port prices across all fuel grades, meaning "discretionary travel" would become much more affordable.