Tauranga motorists could save as much as 9 cents per litre by shopping around and pumping their own petrol.
The saving equates to about $3.60 for 40 litres of fuel.
But a price comparison website shows residents are missing out on the country's cheapest petrol.
In Tauranga, the cheapest price of $2.029 per litre (for 91 octane petrol) was found at the self-service Gull station in Whakamarama, city drivers could find fuel almost as cheap ($2.039) at the self-service Gull station in Merivale.
Waimapu Garage on Oropi Road sells Regular 91 for $2.069 per litlre and they pump the petrol for their customers.
Gull has announched today that they have dropped their prices for a second time this week. This means that prices at Gull's unmanned sites have dipped below the $2.00 a litre price point.
Two men seen filling up at the Merivale station yesterday afternoon said they specifically came to the station because it was the "cheapest in town".
However fuel was much cheaper in Rotorua, the men said.
A Caltex station within 5km of the Merivale station was selling 91 octane yesterday for a posted price of $2.119 per litre, while most stations in Tauranga had an average price of $2.088 per litre.
Motorists are also travelling from Bethlehem to Mount Maunganui for cheaper petrol.
AA petrol watch spokesman Mark Stockdale said Gull's unmanned stations usually offered motorists the biggest savings on fuel prices.
"They don't have additional staffing costs and they don't have additional overheads from operating a larger site with a shop.
Petrol was selling at $2.089 per litre at the beginning of the week - the lowest average national price since July, Mr Stockdale said.
Read more in today's Bay of Plenty Times