Queensland and South Australia Diesel Spreads Are Suspiciously Tight While Other States Show 160 Cent Gaps

Queensland and South Australia Diesel Spreads Are Suspiciously Tight While Other States Show 160 Cent Gaps

This week's fuel price data uncovers a pattern that deserves closer scrutiny. While diesel prices across most of Australia show massive variation between the cheapest and dearest servos, two states stand out for how little their prices move. Queensland and South Australia are posting diesel spreads so tight they raise some serious questions about competitive pricing.

Let me walk you through the numbers, because they tell an interesting story.

The tale of two Australias

Across Queensland, the cheapest diesel sits at 307.7 cents per litre and the most expensive at 329.9 cents. That is a spread of just 22.2 cents across 77 stations. South Australia tells a similar story, with diesel ranging from 300.0 to 333.9 cents, a spread of 33.9 cents across 46 stations.

Now compare that to Victoria, where the gap between cheapest and dearest diesel is a staggering 160.1 cents. Motorists in Moolap can fill up for 203.9 cents per litre while someone across the state pays 350.0 cents. Western Australia shows a 137.5 cent spread, with Kununurra offering diesel as low as 199.5 cents while other WA servos charge 337.0 cents. And in the Northern Territory, the spread hits a remarkable 251.7 cents, from 147.3 to 399.0 cents.

So why are Queensland and South Australia so uniform?

Digging deeper into the numbers

A tight price spread can mean one of two things. Either competition is working well and keeping everyone honest, or the market has settled into a comfortable consensus where nobody is willing to undercut anyone else. The difference matters enormously for motorists.

In Queensland, the average diesel price sits at 318.7 cents, up 1.2 cents from yesterday. That is notably close to the NSW average of 319.6 cents and Tasmania's 319.0 cents. But those states show vastly different internal dynamics. NSW has a 161 cent spread across more than a thousand stations, meaning there are genuine bargains to be found if you know where to look. Finley in the NSW Riverina is still offering diesel at 198.9 cents, a full 120 cents below the QLD average.

South Australia averages 320.6 cents for diesel, the highest of any state today. With a spread of only 33.9 cents, there is almost nowhere in Adelaide or regional SA where a motorist can find a genuinely competitive price. The cheapest SA diesel at 300.0 cents would be considered expensive in parts of Victoria where suburban servos are offering prices in the low 200s.

Where the bargains actually are

A closer look at the suburb level data reveals just how uneven the national picture is. In Victoria, the savings available to informed motorists are substantial. Eltham has diesel from 199.9 cents, Cranbourne West from 225.9 cents, and Cobram from 255.9 cents. Even across Melbourne's northern suburbs, Coburg is showing diesel from 299.9 cents while Campbellfield starts at 306.5 cents.

In WA, Kununurra is the standout at 199.5 cents, though the average across that town's five stations is 286.4 cents, which tells you one servo is doing the heavy lifting on competition. Perth metro areas like Bassendean, Kwinana Beach, and Malaga are all showing diesel starting around 299 cents.

Meanwhile in Queensland, no suburb is posting diesel below 307.7 cents. Not one.

The bigger picture on unleaded

While diesel dominates today's notable movements, unleaded petrol shows its own patterns worth watching. Victorian motorists are seeing prices shift in opposite directions depending on their suburb. Glen Waverley unleaded has dropped 12.3 cents to 253.6 cents, while Wallan has climbed 11.4 cents to 261.9 cents and Bendigo is up 12.5 cents to 255.9 cents. That kind of suburb level variation is exactly what competitive markets look like, for better or worse.

The contrast with Queensland's uniformity is striking.

What motorists should know

The variation between states is not just a statistical curiosity. It has real implications for household budgets. A truckie filling a 200 litre tank in Queensland at the state's cheapest rate of 307.7 cents is paying $615.40. That same fill in Kununurra at 199.5 cents costs $399.00, a saving of more than $216 on a single tank.

For Queensland and South Australia motorists, the message is straightforward. The tight pricing in your state means there is limited ability to shop around for a bargain. Whether that is because of genuine cost pressures or a lack of competitive tension is worth investigating further.

Armed with this information, motorists can make informed decisions and avoid paying more than necessary. Use our interactive fuel map to compare prices in your area and check whether your local servo is giving you a fair deal.