Fairfield Servos Price Diesel Within Half a Cent as NSW Claims the Mainland's Cheapest Diesel
The number that caught my eye this morning is 0.4 cents. That is the entire spread across the four diesel outlets tracked in Fairfield, which run from 235.5 to 235.9 a litre. In a market where some suburbs spread more than 20 cents across a few kilometres, that is about as close to perfect price matching as the data ever shows.
It caps an interesting morning for NSW. As of 10th Aug 2026 8:12am AEST, the state's diesel average lifted 5.4 cents to 250.6, the largest rise of any state overnight. The headline number hides the better story, though. NSW has quietly become the cheapest mainland state for diesel, a position Queensland held when I wrote about Mackay just a week ago. Queensland now averages 251.7, Victoria sits at 251.1, Western Australia at 251.6, and NSW, even after this morning's lift, comes in at 250.6. The state also holds the cheapest single pump at 196.9, the lowest credible diesel reading anywhere in Australia this morning.
Sydney's southwest is doing the heavy lifting
Three suburbs in Sydney's southwest are anchoring the state average. Fairfield averages 235.6, Smithfield 236.0 and Greenacre 236.5, all roughly 14 to 15 cents below the state figure.
The spreads interest me more than the averages do. Fairfield's four servos sit within 0.4 cents of each other. Greenacre's four span 21.3 cents, from 224.7 to 246.0. Statistically speaking, these are two completely different markets operating a short drive apart. In Fairfield, any servo will do. In Greenacre, choosing the right one saves close to $13 on a 60 litre fill. Checking current diesel prices before you commit matters far more in suburbs with wide spreads than in tight ones.
Bomaderry leads the state on value
The cheapest NSW suburb in this morning's data is not in Sydney at all. Bomaderry, on the northern bank of the Shoalhaven River, averages 231.4 with its cheapest pump at 215.5, a substantial 19.2 cents under the state average. Neighbouring Nowra, directly across the bridge, averages 240.8, so crossing the river is currently worth around 9 cents a litre.
The caution is Bomaderry's own spread: 24.4 cents, the widest of any NSW suburb in today's value list, which means that 215.5 outlet is doing a lot of the work. Fill at the wrong Bomaderry servo and you could pay 239.9, which rather undoes the trip across the bridge.
Regional NSW is holding steady
Elsewhere the regional picture is unusually consistent. Mayfield in Newcastle averages 237.7 with a cheapest pump of 229.5. Wyong on the Central Coast sits at 239.8, Wauchope near Port Macquarie at 240.9, and Oberon in the Central Tablelands at 240.4 with a spread of just 4.0 cents across four stations. Oberon mirrors the Fairfield pattern: where servos price close together, the average tells you nearly everything you need to know.
One outlier in the snow country
The sharpest single move in NSW this morning was not diesel at all. Premium 98 in Cooma lifted 20.4 cents to an average of 240.3 across eight stations. Cooma is the gateway to the Snowy Mountains and August is the peak of the snow season, so firm demand through town is no surprise. Anyone driving a performance car up the Monaro Highway can compare premium 98 prices before leaving Canberra or the coast rather than accepting the first price in town.
What the numbers mean for your next fill
Three things follow from the data.
- NSW is the cheapest mainland state for diesel at 250.6, despite recording the largest overnight rise in the country.
- Suburb spreads matter as much as suburb averages. Greenacre and Bomaderry both hide gaps of more than 20 cents inside a single postcode.
- Tight markets like Fairfield and Oberon remove the guesswork, with every servo priced within a few cents.
The numbers are clear: NSW diesel buyers are in the strongest position of any mainland state this morning, but only if they treat the state average as a starting point and check the spread in their own suburb before filling up.
