The oil crisis has not only caused petrol prices to soar, it has revealed just how little competition there is among the big oil companies. A couple weeks ago the ACCC announced that it would be looking into uncompetitive behaviour by petrol companies in the rural areas.
The article shows how petrol price rises have been affected in different parts of Australia.
https://thepoint.com.au/news/260327-petrol-prices-are-soaring-in-sync-collusion-or-coincidence
Do you mean they usually buy different oil?
wat
Well old mate said they are buying the same oil. But there are clearly different patterns in the graph… which infers is they are buying the same oil now, then they must have been buying different oil before when there was clear variation in prices.