In January, petrol prices ranged from 170c to 172c per litre in Whangarei while, on Tuesday at 11am, they were 201c to 204c per litre.
Mr Stockdale said the reason the region enjoyed such low prices for so long was because of the "Gull effect".
Gull has lower fuel prices than other stations which means areas where it operates often have lower prices overall.
"So Gull would have lowered their price and then other companies, to stay competitive, would have also lowered theirs.
"The problem is that the price of oil wasn't any cheaper so stations were lifting gas prices elsewhere to help fund lower prices in areas like Northland," he said.
Motorists filling up at Gull Whangarei felt okay about the price rise with some saying they expected it sooner or later.
Joseph Andrews, of Kaikohe, said he used to drive more places while fuel was cheap.
And he said he took advantage of the prices in Whangarei because the prices in Kaikohe were a "rip-off".
Nicki Downie, of Maungakaramea, said she looked up at the prices while filling up and was happy she had her 6c off coupon.
"For me when it was low, I felt like I had more sense of freedom," she said.
However, Ms Downie said the higher prices would not restrict her driving.
One motorist, Terence Pugh, only felt the sting of expensive fuel because he was visiting Whangarei from Sydney.
"It's a lot better over there. When I left we were paying $1.30," he said.
Mr Stockdale said the highest price in Whangarei - 204.9c - was considered to be the "national price".
"What this means is that people are going to have to consider using loyalty programmes and supermarket vouchers to save money, where as before it'd always be cheaper to drive into Gull," he said.
Motorists elsewhere in Northland used to look at Whangarei's petrol prices with envy.
On some days, the price difference between the Bay of Islands and Whangarei could be more than 30c, with the gulf even wider in more isolated locations.
Yesterday, however, the price in Kerikeri, 204.9c, was the same as the standard price in Whangarei.
Bay of Islands drivers had been looking forward to a sharp price drop next month when Gull is due to open an unmanned petrol pump in Waipapa. Gull's new pricing policy, however, makes any major price reduction look unlikely.
January and May comparison
•Whangarei - Gull Otaika: 172.9c to 201.9c
•Caltex Tarewa Rd: 172.9c to 204.9c
•Z Porowini Ave: 172.9c to 204.9c
•Mobil Walton St: 170.9c to 204.9c