Northland drivers are being offered some of New Zealand's lowest priced petrol.
According to website petrolwatch.co.nz, several Northland stations were selling fuel at $2.009 per litre on Tuesday.
At the beginning of the week, AA's national average price for petrol was $2.089 per litre.
Northland is one of several provincial centres where motorists are saving big at the pump.
Motorists in Rotorua and the Wairarapa are benefiting from a similar surge in local market competition contributing to low prices.
Service stations in some regions are selling petrol for as low as $1.999 per litre.
Referred to as the "Gull effect", New Zealand's petrol minnow is forcing prices down in places it operates.
Whangarei Budget Advisory services advises people to shop around for the best price.
"It would make sense to just shop around and see what garages can offer," budget adviser Moana Kingi said.
"But it does come down to distance and how far you are [from the service station]."
AA petrol watch spokesman Mark Stockdale said Gull's unmanned stations usually offered the biggest savings.
"They don't have additional staffing costs and they don't have additional overheads from operating a larger site with a shop.
"Some of the Gull sites in Otaki and the Wairarapa are unmanned and those sites are 10 cents below the national price and that's what we'd expect," he said. "Where those sites exist, the competitors nearby are matching those prices."
Mr Stockdale said most service stations were independently owned and set their own petrol prices.
"For over a year, we've seen substantially low prices in Rotorua, as much as 20 cents per litre lower than the national average.
"That's the pricing decision of the local service station owners and it's great for motorists."
Gull retail business manager Graham Stirck said price variation between Gull stations was due to different subsidies.
"We discount some sites and others we don't. It moves sometimes, so we might discount one and change it to another one."
The company's general manager Dave Bodger yesterday challenged competitors to lower prices in areas where Gull did not operate.
"I'd pat the opposition on the back if they could actually respond in markets where Gull isn't because they never drop their prices there," he told Radio New Zealand.
But Mobil spokesman Alan Bailey warned many service stations would struggle with a price drop.
"The price which we retail fuel is designed to cover the cost of the fuel and ensure that, as far as practical, there is a contribution to profit at the end of the day," he said.
How it rates:
Northland petrol prices
91 Octane: (as at Nov 6)
Z Energy: $2.009
Gull: $2.029 (Nov 7)
Gas Alley: $2.069 (Nov 4)
Tauranga petrol prices
Z Energy: $2.089
Z Energy: $1.999
- Source: pricewatch.co.nz