G7 diesel reserve release: will Queensland diesel get cheaper?

TL;DR: 287.7 c/L. That is the Brisbane metro diesel median on 7 October, down 1.2 cents since the G7 announced a reserve release of up to 100 million barrels on 2 October. Wholesale has moved less: the Brisbane diesel terminal gate price is 266.0, down 0.3 since the announcement. The real wholesale fall came earlier: the gate price dropped 12.8 cents from its 22 September peak before the G7 said a word. Nothing in the data shows the release at a Queensland bowser yet. Whether cuts are still owed at today’s gate price depends on the yardstick: against the 18-month gap of 22.7, the pump-to-gate gap of 21.7 shows no backlog of cuts; against the past 30 days it is 4.7 wide. The money on the table today is the spread: the cheapest metro diesel currently reported as available is 267.5, worth $14.14 on a 70-litre fill against the median.

There is a Whirlpool thread titled “Diesel price gouging”. Its opening post points at Western Australia’s FuelWatch metro averages for a Monday 23 March, diesel 140.2 and unleaded 110.8: diesel 29.4 cents dearer.

In Brisbane tonight the same gap is 48.8. The metro diesel median is 287.7 and regular unleaded is 238.9. That gap is why a diesel reserve release is news in a ute. So the question this week: the barrels are coming, when does my fill get cheaper?

What was announced

The ABC reports the G7 has agreed to release “100 million barrels of diesel and crude oil from their reserves over four months”, “to begin immediately”, “including a front-loaded substantial diesel release within the first 20 days”. The report does not mention Australia and does not say how many of those barrels are diesel. The Irish Times reports that France had earlier proposed Europe release 50 million barrels of diesel with other IEA countries adding 50 million of crude, and that the G7 statement did not make the split clear. The ABC’s own summary line puts it at “up to 100 million barrels”, and Bloomberg and NBC use “up to” as well, so I do too. The announcement was made on 2 October overseas, which was early on 3 October in Brisbane. That makes 2 October the last reading here before the news.

Wherever you fill up in Australia, the path is the same. The release has to lower the world price of diesel, the Aussie dollar converts it, that lands in the terminal gate price at your nearest terminal, and the pump follows on a lag. For Brisbane I can measure the last two steps.

What we checked

Has Brisbane diesel moved since 2 October by more than it was already moving? I set the daily pump median, from the prices 471 to 473 metro stations reported to the Queensland Government feed, against the Brisbane diesel terminal gate price published by the Australian Institute of Petroleum. My starting line is 7 September, a month back and before the steep part of the climb, when the gate price was 243.3.

What the data shows

Wholesale peaked at 279.1 on 22 September. By 2 October it was 266.3. Today it is 266.0. Of a 13.1 cent fall, 12.8 came before the announcement and 0.3 after.

The pump barely followed. I last wrote the metro median up on 23 September, after the plateau had broken. That post had 289.5 for 23 September and 289.9 live, from a box around the CBD and an earlier cut of the day. This post uses a wider 30 km panel and an end-of-day cut, and on that measure the median held 290.9 from 23 to 26 September and sits 3.2 below that now. Since the announcement, 165 of 472 stations have cut, 38 have raised and 269 have not moved. Statewide, across 1,765 stations, the median is 285.9, down 1.0 since 2 October and still up 29.0 on that 7 September starting line.

Why so little at the pump against 13.1 at the gate? When I measured the two-week lag between wholesale and the pump, falls passed through faster than rises, about 56% at the two-week mark. The two weeks have not run yet. This fall started on 23 September, and 12.0 of the 13.1 landed between 23 and 30 September, so the two-week mark for the bulk of it is about 14 October. On that average, roughly 7 cents would be at the pump by then. So far the pump has given 2.2 measured from the day of the gate peak, 22 September (289.9 to 287.7), and 3.2 measured from its own later peak.

There is a second way to read it, and it is that the pump never caught the peak. On 22 September retail sat only 10.8 over wholesale. The long-run gap I measured in that lag post, over the 18 months to July, is 22.7. The lag worked in our favour on the way up: wholesale turned before the pump finished climbing. Add 22.7 to today’s gate price and you get 288.7, a cent above where the median actually is.

Those two readings point in different directions. The lag average says about 5 more cents could reach the pump by mid-October. The long-run gap says the pump is already where today’s gate price puts it. I cannot settle that from one fall, and I am not going to let either one win by default.

Here is the part a driver who suspects gouging should see. Today’s gap of 21.7 is normal against 18 months and wide against recent weeks. The gap has averaged 17.0 over the past 30 days and 13.6 over the past 90, squeezed while wholesale was climbing. The widest it reached in those 90 days was 22.6, last week. So 21.7 is back at the 18-month norm and near the widest in three months. From 22 September the sums close: the gate fell 13.1, the pump fell 2.2, and the other 10.9 went into rebuilding that gap, from 10.8 to 21.7.

Upstream, Brent is about US$101 a barrel on 7 October (Trading Economics, one live quote). That is about 8 dollars under the roughly US$109 I quoted on 16 September and again on 23 September, so the barrel had already eased. OPEC+ agreed on 4 October to “keep targets steady for November” (Moscow Times). The dollar was “around 0.6970” on 6 October (Tradingpedia), against about 72 US cents in that 16 September post. A weaker dollar hands back part of a cheaper barrel: about 7% cheaper in US dollars is closer to 4% in ours. That is the same size as the gate fall: 13.1 cents off 279.1 is 4.7%. A barrel that eased from late September and a gate price that fell from 23 September line up with each other. Most of that came before the G7 did: Brent was reported closing at US$102.31 on 1 October, the day before the announcement. The barrel did dip further on the day, under US$100 by most reports, and has since given most of that back. None of it has shifted the Brisbane diesel gate price this week.

Petrol is a different story. The Brisbane unleaded gate price is up 6.0 since 2 October, from 233.3 to 239.3, which puts it 0.4 above the metro pump median of 238.9. That gap has averaged 6.4 over the past 90 days, so petrol drivers have less cushion tonight than diesel drivers do.

The verdict

Not yet, and not by anything I can measure. The announcement changed nothing visible in Brisbane diesel wholesale. Against the long-run gap the pump has no backlog of cuts to pass on. Against the 30-day average of 17.0 it is running 4.7 wide, and the lag average would have about 5 cents still to arrive by mid-October. I cannot tell you which of those the next month will look like. For diesel to get meaningfully cheaper here, the gate price has to fall further first. If the 20 front-loaded days are counted from 2 October they run to 22 October. That is the window to watch.

What it means for your fill

• Nothing measured so far says waiting pays. The median has moved 1.2 cents in five days. The most the lag average points to is about 5 more by mid-October, and that is an average, not a promise.
• The spread is ten times the five-day move. In tonight’s live pull of stations currently reporting diesel as available, the metro median is 287.9, the cheapest tenth of stations are at or under 275.9 and the dearest tenth at or over 293.9. Median to cheapest tenth is 12.0 cents: $8.40 on 70 litres, $21.60 on 180.
• The floor is 267.5, at ten Freedom, United, Liberty, Mega, Pearl and Solo stations around Rocklea, Acacia Ridge, Archerfield, Coopers Plains, Oxley, Sherwood and Darra. Against the 287.7 median that is $14.14 on 70 litres, $36.36 on 180.
• Check before you drive. Nine of those ten last reported on 6 or 7 October. Mega Fuels Rocklea last reported its 267.5 on 3 October. A station reports when its price changes, so an older timestamp is not a wrong price, but it is the one to look at first. Pick diesel on fill.pinly.com.au and you are looking at the price each station itself reported to the Queensland Government feed.

Honest limits:

• Scope and timing. Pump figures here are Queensland only. 7 October is a part day, pulled about 9pm, and the median can shift a few tenths by midnight. The station count runs 471 to 473 from 1 September to 7 October. The headline label runs from 10 July because the 90-day gap average reaches back that far.
• Two medians, two methods. The 287.7 is the daily panel: 472 stations, each one’s last reported price carried forward. The 287.9 is the live pull: the 471 stations currently marked as having diesel available. The panel does not filter on availability.
• The 45-day cap. The panel drops any price last reported more than 45 days before the day in question. Without that cap the 7 October metro median is 286.9 across 474 stations, not 287.7 across 472.
• Stale Pearl listings. The panel does not filter on availability, so it carries four old premium diesel prices at Pearl Energy sites that are no longer marked available, last reported 23 to 25 August: 238.5 at Moorooka and at Woodridge, 239.5 at Rothwell and 245.5 at Acacia Ridge, which is one of tonight’s ten 267.5 stations. They sit in every day of the panel back to late August and pull its median down slightly, which is part of why it sits under the live figure, and those four stations count among the 269 “not moved” whatever their real price did. Rothwell’s 23 August listing sits right on the 45-day cutoff and leaves the panel on 8 October.
• The floor and the dollar figures. The 267.5 is the cheapest station currently reporting diesel as available, counted at ten stations at about 9.20pm. The $14.14 and $36.36 set that live floor against the panel median; against the live median of 287.9 they are $14.28 and $36.72, so the figures in the post are the conservative pair.
• Differences from my 23 September post. That post published 273.9, 285.5 and 289.5 for 16, 18, and both 21 and 23 September. This panel has 276.4, 287.9, 289.9 and 290.9 for those four days, 0.4 to 2.5 cents higher. That post used a box around the CBD and an earlier cut of each day; this one uses a 30 km radius and an end-of-day cut, and I have not re-run the old method here.
• The gap figures. The 22.7 is the 18-month median gap to July 2026 from the lag post and was not recomputed for this post. The “no backlog” line holds only against that long-run figure and is an inference, not a forecast. The 30-day and 90-day gap averages count weekends at Friday’s gate price.
• The lag figures. The 56% is a two-week average from a thin sample that shifts with the threshold used. The “roughly 7 cents” and “about 5 more” are my arithmetic on it, not measurements, and 14 October is where two weeks lands for the bulk of the fall, not a countdown.
• Wholesale. Gate prices for 5 to 7 October (266.6, 266.8, 266.0) are from AIP’s daily page and will be re-checked against its next weekly file.
• Upstream. Brent is a proxy. Australian diesel is priced off refined diesel in Singapore, not crude, and this release is diesel-led, so Brent can miss a move in the diesel price itself. Brent and the dollar are single quotes reported by others, and the 7% and 4% are my arithmetic on them. The match between that 4% and the 4.7% gate fall is a rough one: the gate price includes excise and GST that do not move with the barrel.
• Petrol. The 48.8 gap to petrol is the same panel’s regular unleaded median, 238.9 across 439 stations.
• External reports. The ABC’s body text gives a flat “100 million barrels” and its summary line says “up to 100 million”. The 50 and 50 split is a French proposal as reported by the Irish Times, not a confirmed breakdown. The Whirlpool figures come from a search snippet of the thread’s opening post: I could not open the thread to check its wording or its year, so I give only the title and the two numbers. It is there for the feeling, not as a like-for-like figure.
• Assumptions. The 2 October start for the 20-day window is mine; the ABC says only “to begin immediately”. Nothing here separates a G7 effect from a wholesale fall that began on 23 September.

— Tom