@kiwi535 their fuel components come from Singapore
Fun fact - not sure if anyone remembered the Diesel crisis a decade or so about, Gull was the only brand which wasn't contaminated from the sulfur content, i remember there being Bank Run type queues at the stations during the time until the other fuel companies could redo all their Diesel
Things may have changed where they buy from with Caltex purchasing them, but i wouldn't imagine so because they have very specific mixing rules, i.e. the import the components in separately, and mix it into the different fuel grades at terminals New Zealand at Mount Maunganui Hewletts Road,
They make huge savings on Tax brackets, because there are different tax levies if your importing a Fuel Grade, or an un-mixed component which they mix locally to produce the end product at the pump, that's why they are able to always under cut fuel prices, they are at a huge cost advantage to produce.
Gull Bio Diesel gets its components from recycling/refining left over by-products from the dairy industry, by memory they are the only company to implement this process, the other companies have to manufacture the required components for it.
Other companies in NZ get their fuel from Marsden Point
and some from overseas
Not sure who gets what from where, but Gull definitely gets it components ex-singapore and produces the fuel products locally.