Victoria Has the Lowest Diesel Average in Australia but Langwarrin Just Moved the Other Way
At 2:01pm AEST on 11th Sep 2026, Victoria holds the lowest average diesel price of any state or territory, at 258.6 cents a litre across 1,029 servos. That is a touch under NSW at 259.6 and Queensland at 260.3. Yet in Langwarrin, on the edge of the Mornington Peninsula, diesel lifted 8.4 cents in a day to 262.9. A quieter number out of Campbellfield also caught my eye. AdBlue there eased 20 cents.
That leaves three questions. Why are the state averages so close together? Why can one suburb move against its own state? And why does AdBlue not follow diesel at all?
Why the state averages barely differ
Victoria, NSW, Queensland, South Australia and Western Australia all sit between 258.6 and 261.1 cents today. That is a range of just 2.5 cents across more than 4,900 servos.
Diesel is essentially the same product everywhere. It is largely imported and priced off Singapore refinery benchmarks, then sold to retailers at a wholesale price called the terminal gate price. Every state is buying from roughly the same shelf at roughly the same cost, and when the biggest input costs the same for everyone, the averages end up in the same neighbourhood.
Why a suburb can go its own way
Inside Victoria the picture looks very different. The cheapest diesel today is 215.9 cents and the dearest is 339.9, a spread of 124 cents within one state and much wider than the gap between states.
Think of it this way. The wholesale price sets the floor, but what a servo charges above that floor depends on who is nearby. A servo with three competitors within a few minutes' drive has to watch its rivals. A servo with fewer alternatives has more room to lift.
That is the way to read Langwarrin. Its five servos went from 254.5 to 262.9, while the state average moved only 1.3 cents. Nothing changed in wholesale costs overnight to justify 8.4 cents. More likely, one or two servos lifted and the rest followed, which is the pattern you see when competition is loose.
Compare that with Reservoir in the northern suburbs, where the cheapest of three servos is posting 238.9 and the average is 246.7. Down the Princes Highway, North Geelong averages 246.8 with a spread of just 5.8 cents, so those servos are pricing close to one another. Grovedale averages 249.0, and near Bendigo, Epsom has a cheapest board of 240.3.
In your wallet, filling a 70 litre tank at Reservoir's cheapest servo instead of paying the Langwarrin average saves around $16.80. The savings calculator will run the same sum for your own fill.
Why AdBlue does not follow diesel
You might be wondering why AdBlue belongs in a diesel story at all. Most modern diesel utes, vans and trucks need it. It is sprayed into the exhaust to cut nitrogen oxide emissions, and a vehicle uses a few litres of it for every hundred litres of diesel. Economists call this a complementary good. You buy it because you buy the other thing, much like printer ink and a printer.
Complementary goods are linked through demand, though, and their costs can move quite separately. AdBlue is urea mixed with deionised water, and urea is priced in fertiliser markets, which follow natural gas rather than crude oil. So in Campbellfield, a busy freight corridor along the Hume, five servos cut AdBlue from 217.9 to 197.9 cents a litre on the same day Victorian diesel crept up.
For a tradie, a 20 cent drop is small change. For a transport operator buying AdBlue by the drum, it adds up.
What to take from today
State averages tell you about wholesale costs, and those barely differ across the country. Suburb prices tell you about local competition, and that is where the real savings sit.
If you run a diesel vehicle in Melbourne, check the diesel prices around you before filling up rather than assuming your usual servo is competitive. Then watch price trends over the coming days to see whether Langwarrin's lift holds or gets competed back down.
Reading the state number and the suburb number separately is what lets you judge where your own board is likely to head next.
