TL;DR: About 1.0 c/L. That is what the Aussie dollar’s climb back above 70 US cents was worth against Brent’s run to US$116.72 this week, if crude passed through in full. Over the month the dollar’s slide cost about 1.6. And Brisbane’s gate prices aren’t tracking crude closely this month: over the barrels this week’s gates were set on, crude added about 6.2 c/L, the diesel gate took 1.5 and the unleaded gate fell 12.9.
“When you can save $10or$20 [sic] a tank fill up by changing your ant trail of life just 1 or 2 kilometres on the way home.” — Petrolspy iOS review, January 2025
The size of that saving still dwarfs the oil move this week. Crude has added about 9.9 c/L since the barrel last Friday’s gate was set on: $6.94 on a 70 L diesel tank if all of it reaches the pump. The cheapest diesel reported in Brisbane metro in the past 48 hours is $14.98 a tank under the median. That’s cheapest against the median across a 30 km radius, not within 2 km of your route, so your own detour may save less. And as in August, the barrel went up while Brisbane’s petrol wholesale price went down.
The claim
The claim I’m testing: a stronger dollar cushions an oil spike. The dollar is back above 70 US cents, at 0.7035 late Friday (FXStreet, EconoTimes), and Brent is at a six-month high (CNBC). Friday’s 3.14% rise followed Houthi attacks on Saudi energy infrastructure, including an Aramco loading facility at Yanbu (The National, Reuters). Does the stronger dollar take the edge off the dearer barrel?
What we checked
Brent closes from CNBC and The National. The Reserve Bank’s daily exchange rate. The Brisbane terminal gate price (TGP), the published wholesale list price, from the Australian Institute of Petroleum (AIP). And what 439 Brisbane stations report for regular unleaded (91), and 473 for diesel, to the Queensland Government feed, taken as a daily median within 30 km of the CBD.
The conversion works for any Australian driver: the change in the Australian-dollar barrel price, divided by 158.987 litres, plus GST. At about 70 US cents, US$1 a barrel is about 1.0 c/L. Excise is fixed per litre and doesn’t move with crude.
What the data shows
I use three windows below, because the gate price trails the barrel by at least a day. Brent’s calendar week, 16 to 23 October, for the dollar (5.85 c/L). The barrels the two gate prices were set on, 15 to 22 October, for the gate (6.2 c/L). And 15 to 23 October for the total that could still reach the gate (9.9 c/L).
The dollar took about 14% off the week’s move. Brent went from US$109.86 on Friday 16 October to US$116.72 on Friday 23 October, up 6.24%. The RBA rate went from 0.6947 to 0.7006, so in Australian dollars the barrel went from A$158.14 to A$166.60, up 5.35%. That is 5.85 c/L crude-only, against 6.83 had the dollar stayed at 0.6947. At FXStreet’s late-Friday 0.7035 the difference is about 1.45 c/L. Real, but small.
Over the month the dollar didn’t help, it added cost. On 23 September the RBA rate was 0.7102. It has fallen 1.35% since, to 0.7006. At Friday’s US$116.72, that adds about 1.6 c/L against a steady dollar. Through September the RBA rate ran between 0.6977 and 0.7232, so whether the dollar helped depends on the day you start the clock. Over a year it has, as of 16 October: in my 18 October post the dollar was 7.0% stronger than a year earlier, worth about 7.7 c/L at US$110. I haven’t re-run that at Friday’s rate.
Last week’s 3.9 c/L didn’t show in full. On 18 October I wrote that Tuesday 20 October’s file was the first likely to show Brent’s US$3.94 jump. The diesel gate rose 0.6 on Monday the 19th, gave 1.0 back on the 20th, and is up 1.5 since 16 October. No file to 23 October shows the full 3.9. The diesel gate went 264.8 on 16 October, 265.4 on the 19th, 264.4 on the 20th, 264.6 on the 21st, 265.4 on the 22nd and 266.3 on the 23rd. The unleaded gate fell every day: 235.4 on 16 October, then 232.3 on the 19th, 229.6 on the 20th, 226.1 on the 21st, 224.3 on the 22nd and 222.5 on the 23rd. The pump estimates in that post assumed the gate would take the full move. It hasn’t yet, so they haven’t been tested.
Line the windows up and the mismatch is wider. As in my 18 October post, each gate is set against the barrel a day earlier. Friday 16 October’s gate was set on Thursday’s barrel, about US$105.9 at 0.6955. Friday 23 October’s was set on Thursday 22 October’s, US$113.17 at 0.7018. Over that window crude added about 6.2 c/L. The diesel gate rose 1.5. The unleaded gate fell 12.9. Crude isn’t the main thing moving Brisbane’s wholesale price right now. The gate follows Singapore prices for refined fuel, not Brent. I don’t hold a Singapore series, so I don’t know why it fell, and I won’t guess.
The diesel pump barely moved. The diesel median went from 284.9 on 16 October to 285.5 on the 19th, back to 284.9 on the 20th, and settled at 285.9 from 22 October. That’s too small to tell flow-through from noise. The gate rose 2.4 from its 263.9 low on 14 and 15 October to 266.3 on the 23rd. It had eased 1.3 to 16 October, from 266.1 on 8 October to 264.8. That’s a wider window than the week I called flat on 18 October, 265.2 on the 9th to 264.8 on the 16th. I’m not calling it.
Diesel tracks its gate. Petrol doesn’t, much. Week to week since January 2025, Brisbane’s diesel median has a 0.88 correlation with its gate price; unleaded’s is 0.19. October shows it. The diesel pump sat between 19.6 and 23.7 above its gate. Today it is 19.6 (285.9 − 266.3), October’s narrowest, down from 20.1 on 18 October. That is under all three yardsticks from my 11 October post as last published: 22.7, 20.5, and the rolling 30-day median, which was 21.0 for the 30 days to 16 October. That leaves less room to soak up a gate rise. The unleaded pump swung from 1.7 under its gate on 9 October to 15.0 over on Friday 23 October. Petrol’s gap over the gate price is 14.4 today, near its 15.7 median since January 2024. That’s because the gate fell, not because the pump rose.
What’s next. Friday’s jump from US$113.17 to US$116.72 is about 3.5 c/L crude-only at a steady dollar, 3.7 with Friday’s dip in the dollar from 0.7018 to 0.7006. Add it to the 6.2 and crude has added about 9.9 c/L since the barrel the 16 October gate was set on, about A$152.3 then against A$166.6 now. That is roughly last week’s 3.9 plus this week’s 5.85. The diesel gate has taken 1.5 of it so far. The gate trails Singapore’s trading day, so Monday 26 October’s file is the earliest that could show Friday’s move, and Tuesday’s is more realistic. I said the same about Tuesday 20 October, and it didn’t show in full, so read that as the earliest, not a promise. This week the diesel gate rose by less than crude. That can reverse: if Singapore refining margins widen, the diesel gate can rise by more than crude.
The verdict
True, for one week. The stronger dollar was worth about 1.0 c/L against Brent’s run to near US$117, at full pass-through. Over the month it cost about 1.6. And for now it barely matters, because Brisbane’s gate prices aren’t following crude closely this month. Over the barrels they were set on, crude added about 6.2 c/L, the diesel gate took 1.5 and the unleaded gate went the other way. Count Friday and crude is up about 9.9 c/L since the barrel the 16 October gate was set on, most of it not yet in any gate price.
What it means for your next fill
- Diesel: crude has added about 9.9 c/L since the barrel the 16 October gate was set on. If all of it passed through, that’s $6.94 on a 70 L tank; this week’s 5.85 alone is $4.10. The gate has taken 1.5 so far. The cheapest diesel in Brisbane metro is 261.5, at Pearl Energy Manly West, Pearl Energy Cannon Hill and Shell Tingalpa. Those were reported 8.03am to 9.41am Thursday 22 October, so they may have moved: the gate rose 0.9 on Friday after them. That is 24.4 under the 285.9 median: $17.08 a tank, about 2.5 times the 9.9 c/L oil move. The cheapest reported in the past 48 hours is 264.5, at Caltex Wilston and U-Go Lutwyche (5.27am and 9.17am Friday 23 October): 21.4 under the median, $14.98 a tank, still about twice the oil move.
- Petrol: if the 9.9 all passed through, $4.96 on 50 L, though the unleaded gate has gone the other way, down 12.9 since 16 October. This week’s 5.85 alone is $2.93. The cheapest regular unleaded is 221.9, at Mega Fuels Rocklea and U-Go Rocklea (reported 9.15am and 10.42am Saturday 24 October), 15.0 under the 236.9 median: $7.50 a tank, about 1.5 times the oil move. The median is at the bottom of its recent range: it has sat between 236.9 and 240.9 since 19 September. Brisbane’s cycle usually moves about 45 c/L; this month it hasn’t moved. That’s a flat market, not a trough. No cycle is running, so there’s nothing to time.
- All three cheapest prices are under Friday’s gate price: diesel by 4.8 and 1.8, unleaded by 0.6. The gate is a published list price. Retailers may buy on contract and still be selling older stock, so being under it doesn’t mean selling at a loss.
- These are the prices stations report to the Queensland Government, not crowd submissions. The live list is on Pinly Fuel. Check before you drive.
How we measured and honest limits:
- Grades. Unleaded is regular unleaded (91, ULP). Diesel is the diesel family: the cheapest of standard and premium diesel at each station, because many metro sites report diesel only under the premium code.
- Where. Brisbane metro only, within 30 km of the CBD. The c/L conversion applies anywhere in Australia. The gate and pump readings don’t apply to regional Queensland.
- The panel. Each station’s last reported price is carried forward if it was reported in the previous 45 days, then the median is taken across stations. The 1 March to 27 April 2026 data gap is excluded, as in my earlier posts. Gate prices are carried over weekends. The latest AIP file is 23 October.
- Three windows. The dollar figures use Brent’s calendar week, the 16 to 23 October settles (5.85 c/L). The gate comparison uses the barrel a day before each gate, 15 to 22 October (6.2 c/L), because the gate trails the barrel by at least a day. On that window the dollar was also worth about 1.0 c/L (6.2 against 7.2 at a steady dollar). The total runs from the barrel the 16 October gate was set on to Friday’s settle, 15 to 23 October (9.9 c/L): the 6.2 plus Friday’s 3.7. It is close to my 18 October post’s 3.9 plus this week’s 5.85; the small difference is the dollar moving between 15 and 16 October, and that post’s US$1 ≈ 1.0 c/L rounding. The US$105.9 is Thursday 15 October’s settle worked back from Friday’s 3.7% rise, as in my 18 October post. The 22 October close, US$113.17, is worked back from The National’s reported 3.14% rise to Friday’s US$116.72.
- The conversions. All c/L figures are crude-only estimates at full pass-through and include GST. Friday’s 3.5 is the US$1 ≈ 1.0 c/L rule of thumb; the extra 0.2 in the 3.7 is the dollar slipping from 0.7018 to 0.7006. The tank figures are the c/L times 70 L or 50 L.
- The correlations. The 0.88 and 0.19 are week-to-week correlations of price changes from January 2025, on the panel to 16 October, as published on 18 October. I haven’t re-run them to 23 October. The 15.7 is the median pump-minus-gate gap since January 2024, as in my 11 and 18 October posts. The October gap ranges are a different measure, shown as an illustration. The 15.0 over on 23 October is the unleaded pump median minus that day’s gate (237.5 − 222.5); it is a different measure from the 15.0 c/L gap between the cheapest unleaded and the median.
- The diesel yardsticks. The 22.7 and 20.5 are two of the three from my 11 October post. The third, the 30-day median, rolls: it was 19.0 on 11 October and 21.0 for the 30 days to 16 October, as in my 18 October post. I haven’t re-run it to 23 October.
- The petrol cycle. The 45 c/L is Dan’s July figure, the median peak-to-trough drop across 12 swings.
- External figures. Brent’s 23 October settle and the 6.2% week are from CNBC and The National; the 16 October settle is from CNBC and The National. The cause of Friday’s rise, Houthi attacks on Saudi energy infrastructure over the previous 48 hours, is as reported by The National and Reuters, 23 October. The dollar is the RBA’s daily rate (table F11): 0.6955 on 15 October, 0.6947 on 16 October, 0.7018 on 22 October, 0.7006 on 23 October and 0.7102 on 23 September. Through September it ran between 0.6977 and 0.7232. The late-Friday 0.7035 is from FXStreet and EconoTimes. The month’s 1.6 c/L is the dollar alone: Friday’s US$116.72 at 0.7006 against the same barrel at 0.7102, so it doesn’t depend on where Brent started the month. I haven’t used a monthly Brent change: Trading Economics’ figure doesn’t say which close it starts from, it moved as Friday’s price updated, and the 23 September settles I found don’t agree. The year comparison is as of 16 October, from my 18 October post.
- The floors. Cheapest prices pulled at 9.11pm AEST on Saturday 24 October, from stations reporting in the past week; the 264.5 diesel floor is the cheapest among stations whose diesel price was reported in the 48 hours to 9.59pm that night. They go out of date within hours. A station reports when its price changes, so an older timestamp is not a wrong price, but check before you drive.
— Tom