This is crazy. According to Gasby, petrol is $2.936 /L at NPD Porirua, and $3.259 at Z Mungavin Avenue.
That's a 32.3 c/L or 11% increase between two stations 2km apart.
Clearly the invisible cartel (of petrol stations raising and lowering their prices together by watching each other's signs) is a bit broken by the current crisis.