Adelaide Unleaded Has Climbed 25 Cents in a Fortnight Without a Single Reset

Adelaide Unleaded Has Climbed 25 Cents in a Fortnight Without a Single Reset

If you have been filling up around Adelaide over the last two weeks, you have probably noticed something odd. The board keeps going up, a cent or two at a time, and the usual midweek drop never arrives. At 8:11am AEST on 25th Sep 2026, the most common unleaded price across 197 servos within 15 kilometres of the city is 236.9, closely followed by 237.9. A fortnight ago, many of those same servos were charging under 213.

That is not how Adelaide usually behaves, and the way it has happened says a fair bit about what is driving it.

A staircase, not a sawtooth

Adelaide normally runs a price cycle. Prices lift sharply, then competition slowly wears them back down until someone restarts the cycle. Picture a sawtooth: a steep climb, then a gentle slide.

This fortnight looks nothing like that. Take the OTR in Unley. Its unleaded sat at 212.9 on 12 September. It moved to 218.9 by the 14th, jumped to 227.9 on the 16th, then added roughly a cent every night: 231.9, 232.9, 233.9, 234.9, 236.9 and now 237.9. That is 25 cents in thirteen days without a single step back down.

The Caltex on West Terrace in the city took almost the same path, from 209.9 to 237.9, and the OTR in Prospect went from 208.9 to 231.9.

The independents moved too

You might be wondering whether the cheaper independents held out. They did not. The United in Pooraka was at 199.9 on 12 September and now reads 224.9. The U-Go in Clearview went from 201.0 to 224.5. The Ampol in Edwardstown climbed from 202.9 to 224.9, and the U-Go at St Marys from 202.5 to 224.4.

So everyone has risen by roughly the same 23 to 25 cents, and the gap between the cheap end and the expensive end has barely changed. It was about 13 cents two weeks ago, and it is still about 13 cents today.

Why a parallel move matters

When one retailer lifts prices and the others hold, that is usually a margin decision, and competition eventually drags the leader back. When every retailer lifts by the same amount, independents included, the more likely explanation is that the cost of supply has gone up for all of them.

Think of it this way. If your local bakery raised the price of bread by 50 cents, you would suspect the bakery. If every bakery in town raised it by 50 cents in the same week, you would suspect the price of flour. Independents like U-Go, Solo and United carry the thinnest brand premiums and have the least reason to follow a margin grab, so when they climb in step with the majors, the cause most likely sits upstream.

The nightly one cent steps fit this reading too. Instead of one large jump that motorists would notice, the cost is being passed through gradually.

Where the cheaper unleaded is today

Because the spread has held, the northern suburbs are still where the value is. Blair Athol has Solo at 224.5, with Mobil and United both at 229.9. Pooraka has United at 224.9 and Solo at 226.5. The Costco at Blair Athol reads 222.7, although you will need a membership to use it.

In the eastern and inner suburbs, OTR and Caltex boards commonly show 236.9 to 237.9 in Unley, Glenunga and Marryatville. Across the 81 OTR sites in the sample, the average is 236.3. Solo averages 227.5 and U-Go 226.3.

On a 50 litre tank, a 12 to 13 cent gap is worth around $6.50.

What to watch next

Every Adelaide motorist wants to know when the reset will arrive. A staircase like this can end in two ways. If supply costs ease, retailers have room to compete again, and the familiar cycle should return with a sharp drop at one of the independents. If costs keep rising, the steps may simply continue.

The signal to watch for is one of the northern independents dropping 10 cents or more overnight. That is usually the start of the discounting phase, and the rest of the market tends to follow over the next few days. You can track daily movements on our price trends page, check current unleaded petrol prices near you, or read up on the best time to fill up in cycling markets like South Australia.

Knowing whether a rise is a margin decision or a cost decision tells you whether waiting a few days is worth it. Right now, with everyone moving together, filling at the cheaper end of the spread is the more reliable saving.