But Z's stations on Vivian and Taranaki Streets are still selling 91 for $2.239. At BP on Cable St it's priced at $2.209.
So while motorists have the option of buying much cheaper fuel, they'll have to go out of their way to get it.
AA petrol watch spokesman Mark Stockdale said it was early days since Waitomo opened in Thorndon and the market could still react further.
One reason prices haven't dropped could be because commuters from around the region make up the bulk of customers filling up there, he said.
"So the effect of Waitomo opening might not be being fully felt by other service stations in Wellington City. They might not be losing too many customers because people going to Waitomo didn't live and shop there anyway."
Waitomo had undoubtedly brought price competition to Wellington but the impact was a ripple effect based on proximity, he said.
"If people want to access the lower fuel prices that Waitomo are charging it does mean they will actually have to change their behavior and make the effort to travel to Thorndon.
"That shouldn't be that difficult for a lot of Wellingtonians who live in the city suburbs because if you head out of Wellington there's only one way to go and that's north."
But Wellington Chamber of Commerce chief executive John Milford said central city stations might not be losing out on customers precisely because they're on major routes in and out of the city for commuters, whereas Waitomo is less so on Hutt Rd.
The opening of Waitomo's Thorndon site was a good start to addressing the monopolisation of Wellington's fuel market, he said.
"If there were two or three other strategically placed fuel stops with similar offerings, you would start to see pressure building on other companies to reduce their price."
Wellingtonians have been hurting at the pump for some time compared to other areas in the North Island.
At times this year Aucklanders have paid less than those in the capital, even with a fuel tax.
Mayor Justin Lester said competitor petrol stations would be watching Waitomo closely.
"They'll be looking at their customer levels and the amount of fuel they sell and as soon as they see a corresponding decline in their customers they're likely to make changes at the pump."
Fuel company Z is currently selling 91 for the highest price in Wellington.
Each station is priced taking things like location and local competition into account, Z corporate communications and investor relations manager Nicola Law said.
Some competitors offer something materially different to Z, she said.
"Whilst Z has invested in a full service offer (forecourt concierge, forecourt canopy, food and coffee, loyalty rewards), others offer a more basic, no frills type of offer which may not even include a forecourt canopy.
"Customers have a choice as to what is of value to them."
