When petrol jumps 20 cents in a week, it feels arbitrary. It isn’t. A litre’s price is a stack of four parts, and each part moves for its own reasons. Knowing which part moved tells you whether waiting, shopping around, or nothing at all will help.

The four parts of a litre

Take a pump price around $2.00 a litre. Roughly, it splits like this:

  • Wholesale fuel cost (roughly half). NSW petrol tracks the international price for refined petrol in our region, plus shipping. It moves with oil markets and the exchange rate, and no NSW driver or retailer controls it.
  • Fuel excise (about 54 cents as of August 2026). A fixed federal tax per litre, the same on petrol and diesel. It’s indexed to inflation twice a year, in February and August. The Australian Taxation Office publishes the current rate.
  • GST (10% of the total, so about 18 cents at $2.00). Charged on top of everything, including the excise. Yes, that’s a tax on a tax.
  • Freight, retail costs, and margin (the remainder). Trucking fuel to the station, running the site, and the retailer’s cut. This is the only part that differs between the station on one corner and the station on the next.

Why prices jumped in August 2026

The federal government cut the excise temporarily from April 2026. That relief ended on 3 August 2026, and the rate reverted to the full indexed 53.7 cents per litre. A jump of that size lands at every station at once. No amount of shopping around avoids a tax change; it just moves the whole board up.

The cycle sits on top

In Sydney, retail margins swell and collapse in a repeating pattern: prices ratchet up sharply, then discount down for weeks. That cycle is the piece worth timing, and it’s the only piece that is. We cover how it works in the NSW price cycle, explained.

What this means in practice

  • A statewide jump (tax change, oil spike) hits every station. Waiting doesn’t help; the new level is the new level.
  • A cycle spike is local and temporary. The discounting phase follows, and cheaper stations exist during every phase.
  • The spread between stations in the same suburb is often 20 to 30 cents. That spread is the part you control, today, by picking the right station.

Compare live prices near you with the finder, or browse prices suburb by suburb.