Fuel prices in Australia are driven by crude oil costs on global markets, and right now there's a perfect storm. Refinery shutdowns in key regions, supply tightness, and demand picking up faster than expected are all pushing prices up at once. When crude spikes, it hits the pump within days because retailers pass costs through quickly.
The 30-cent jump you're seeing talked about is steep but not unheard of when multiple factors align badly. Currency fluctuations matter too - if the Australian dollar weakens against the US dollar (where oil is priced), that makes imports more expensive. Geopolitical tensions or production issues in major oil regions add another layer of pressure on supply.
There's not much you can do about global market forces, but if you're worried about costs, filling up before any announced hike goes live saves a bit. Some retailers move faster than others, so shopping around still makes sense. After the initial shock, prices usually stabilize once supply catches up or demand eases, so this isn't necessarily the new normal.