The price increases tend to be one sudden jump upwards and then a slow slide downwards too. The different stations used to be fairly synchronised but they are all over the place these days.

I have the Petrol Spy app which tracks the prices at different places and it has a graph which shows the average prices over the last couple of months for each state. The different price pattern between them are crazy. We currently have price cycles that go up then back down over about a month, Perth apparently has dramatic weekly fluctuations. I'm pretty sure Melbourne's price cycles used to be a lot shorter, it would be interesting to have comparison over time as well.

All the petrol stations on Plenty road are the same price from the ring road out to Mernda, regardless of company. Then the first petrol station south of the ring road is 15-20c cheaper. Very interesting