TL;DR: Yesterday, the typical 4km unleaded spread between the cheapest and dearest board in Brisbane was 25.0 c/L — about $13.75 across a 55-litre tank; E10 was 22.4. Across the last 79 weeks the typical spread is about 20 c/L, and at cycle peaks it reaches 62.4. And it isn’t just brand-vs-brand: two Caltexes 2.8km apart posted 199.9 and 164.7 — a 35-cent gap under one logo. The price on the sign is not “the price of fuel near you.” It’s one number in a wide band, and which one you pay is close to luck unless you look.
I drive an E10 Corolla and keep a household budget I’m not embarrassed about. So when a driver tells me two servos of the same brand, minutes apart, are 30 or 40 or 60 cents apart, my first instinct is not outrage. It’s to ask for the number. Here is the number.
The claim
The claim comes in two flavours, and I want to take both seriously. The first is the everyday version, asked in genuine confusion:
“Why does the same petrol station have different prices? Shell station could have $1.59 litre while a shell station just 5 minutes away could cost $1.99 litre” — r/AusFinance
The second is the receipts-in-hand version, from a driver who’d already done the measuring:
“Petrol Spy showed a 60cent/litre price variation in E10 fuel. The distance between the independent and the corporate robber baron was less than 4km.” — PetrolSpy iOS review, 2024
Two questions fall out of that. Does the same brand really charge wildly different prices this close together? And is the whole-market spread inside 4km as wide as drivers say? We can answer both from the feed — and we come back to that 60-cent E10 number in the verdict below.
What we checked
Everything below is the Queensland Government price feed — the price each servo reported charging, not a driver’s guess at the bowser. That matters more here than usual. When someone tells you two servos 4km apart are 30 cents apart, the reflex is to assume one posted a fake number to bait you in. There are no user submissions in any of this. It’s the government feed, so a 30-cent gap is a 30-cent gap.
We took every servo within 30km of the Brisbane GPO that had reported a price in the week to 20 July — about 440 with a live unleaded price, 387 with E10. For the snapshot, we took yesterday, 20 July, and for each servo measured the spread between the cheapest and dearest board of the same fuel within 4km of it. For the same-brand test, we did it again but only paired servos flying the same logo, and we held the same 4km radius so the two tests are directly comparable. And to stop yesterday being a fluke, we ran the same 4km spread weekly across 79 weeks — January 2025 to July 2026, skipping the March–April data gap — so you can see the typical week, not one afternoon. The 79-week series is run for both fuels; the E10 count above (387) is the E10-specific panel, not a copy of the ULP one.
What the data shows
Start with the whole-market spread inside 4km yesterday. This is not brand-vs-brand — this is the cheapest and dearest of any servo within a short drive of you:
- Unleaded (91): the typical 4km spread was 25.0 c/L. On a 55-litre tank that’s about $13.75. The top 10% of servos sat 35+ c/L apart inside 4km, the widest 36.0. (That’s a 4km-radius market spread — a different test from the 34.4 c/L across-the-road corner Shane measured under 300m in the same-day corner post. Different radius, same feed.)
- E10: the typical 4km spread was 22.4 c/L — about $12.32 a tank.
Now the same-brand claim, which is the one that stings. Most same-brand pairs match closely — the median gap between two servos of the same logo within 4km is just 3.0 c/L. If your read is “brands never let their own sites drift apart,” that median is real and I won’t hide it: most of the time, same logo means near-enough same price.
But the tail is a different animal. One same-brand pair in ten is 24.0 c/L apart or more, and the worst yesterday was 35.2 c/L: two Caltexes 2.8km apart, one on Gympie Rd at 164.7 and one on Sandgate Rd at 199.9 — the dearer board sitting right on the 199.9 cycle-peak ceiling metro prices top out at (the same ceiling Shane’s corner post found).
That 35.2 is a coincidence, not a copy of the whole-market figure above: this one is a single same-brand pair, the other was the market-wide spread across the top 10% of servos.
A pair of BPs ran it close — 411 Gympie Rd at 169.5 against Abbotsford Rd at 199.9, also on that peak ceiling, 3.8km apart, a 30.4-cent gap. Two Uniteds sat 30.0 apart and two 7-Elevens about 28 too. It happened under a single brand, on the same day, on the same feed. So the honest verdict on the same-brand claim is: it is not the rule, but it absolutely happens, and when it does the gap under one logo is around a tank’s worth of money.
The verdict
The claim holds, with one correction. “The same brand always charges different prices” is false — most same-brand pairs match to within 3 cents. But “the price near you sits in a wide band, and same brands sometimes land at opposite ends of it” is true and costs real money. Yesterday’s 25-cent unleaded spread inside 4km isn’t a folklore number. It’s the median.
And yesterday was mid-to-late cycle, so it understates the range you’ll see over time. Across the full 79 weeks, the typical week has a 20.0 c/L median spread inside 4km, one week in ten hits 51.6, and at cycle peaks it reaches 62.4. The spread isn’t flat across the cycle either: it’s widest as prices climb toward a peak and narrowest mid-cycle. So the 60-cent E10 gap that reviewer measured wasn’t a one-off — an E10 neighbour within 4km sat 60+ cents apart in 21 of those 79 weeks, better than one week in every four, with the E10 tail reaching 66.4 c/L. The same 79-week window and 4km radius sit behind both fuels.
So what for you
The lesson is not “distrust your usual servo’s brand.” Same logo usually is the same price. The lesson is that the board you happen to be driving past tells you almost nothing about the cheapest board within a five-minute detour — and the gap between them, on a normal Brisbane day, is a tank’s worth of money. On a 55-litre fill, yesterday’s typical unleaded spread was about $13.75 for turning left instead of right. Pinly Fuel shows you every servo’s price around you off the QLD Government feed, so you can see where you sit in that band before you pull in, not after.
The honest limit
“Minutes apart” here means within about 4km in a straight line, not measured drive time — a 4km gap over the river is not a two-minute detour. The same-brand test is pair-based: it compares two sites under one logo that sit within 4km of each other, so the “median 3.0” is a same-logo pair gap, not a per-chain average across a brand. The dollar figures assume a 55-litre tank; scale to yours. Yesterday’s snapshot is one mid-cycle afternoon, which is why the durable headline is the 79-week range, not the single day. And the same-brand story is a tail, not a rule: the two Caltexes are an “it happens” case, not proof that a brand coordinates its sites — most of the time its sites match. I’ve left out one placeholder value the feed sometimes posts (999.9 c/L, a data error, not a real price), bounded everything to sane prices, and every spread is a straight-line 4km cut.
This is petrol — ULP and E10. Diesel runs its own map and its own spread, so if you’re filling a ute, Tom has the diesel version coming separately.
— Priya