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# Diesel refining margins hit US$100 before the Australian harvest
- URL: https://www.bushletter.com/diesel-refining-margins-hit-us100-before-the-harvest/
- Published: 2026-09-20T22:30:00.000Z
- Updated: 2026-09-20T22:29:59.000Z
- Description: Russia suspended fuel exports through January 2027 following drone strikes on its infrastructure, leaving Australia exposed to international wholesale prices for 90 per cent of its refined fuel needs.
- Author: Editor
- Tags: Energy, Australia

![Alex Mercer](https://res.cloudinary.com/dz77sb7j1/image/upload/v1774262566/bushletter/authors/alex-mercer.png)

By **Alex Mercer** · 2026-09-19

TLDR

The margin refiners earn turning crude into diesel broke US$100 per barrel on 17 August 2026, driven by war-related refinery outages in the Middle East and Russia. Australia imports about 90 per cent of its diesel, so pump prices track refining margins directly, and farmers heading into harvest say they cannot absorb the extra cost.

KEY TAKEAWAYS

01The U.S. Gulf Coast diesel crack spread broke US$100 per barrel on 17 August 2026, a record high.

02Russia suspended diesel exports through January 2027 after Ukrainian drone strikes crippled its refinery network.

03Middle Eastern refinery outages tied to conflict around the Strait of Hormuz tightened global processing capacity further.

04National Farmers' Federation president Hamish McIntyre warned some growers may scale back plantings if costs stay elevated.

05Australia's roughly 90 per cent import dependence means local diesel prices track refining margins, not crude alone.

## The margin, not the oil

The global oil market is not short of crude. Refining capacity is the constraint. The U.S. Gulf Coast diesel crack spread surpassed US$100 per barrel on 17 August 2026, the first time that threshold has ever been crossed.[\[1\]](https://rbnenergy.com/daily-posts/blog/100bbl-diesel-crack-or-how-2026-exposed-fragility-global-refining?ref=bushletter.com) For comparison, the broader NYMEX 3-2-1 crack spread sat around US$69 per barrel on the same day, itself up from a pre-2026 range of US$19 to US$25 per barrel.[\[2\]](https://app.hedgeye.com/insights/186113?ref=bushletter.com)

A crack spread is the arithmetic difference between the wholesale price of a refined product and the cost of the crude feedstock that produced it: the refiner's gross margin, nothing more. When that number trebles in under a year, refiners win and everyone downstream pays.

## Two wars, one bottleneck

Diesel is harder to make than petrol. Specific hydroprocessing and catalytic cracking stages are required, so when refinery capacity disappears, diesel prices respond faster and more sharply than petrol prices. Two geopolitical shocks removed a material slice of that capacity at roughly the same time.

Russia suspended diesel and gasoline exports through January 2027 after Ukrainian drone strikes crippled its refining infrastructure.[\[2\]](https://app.hedgeye.com/insights/186113?ref=bushletter.com) Conflict-related disruptions around the Strait of Hormuz took Middle Eastern refineries offline at the same time, reducing regional processing capacity further.[\[2\]](https://app.hedgeye.com/insights/186113?ref=bushletter.com) Global diesel supply loses volume precisely when a key transit route for crude and refined products becomes unreliable.

Hedgeye Risk Management analyst Daryl Jones said: "Crude is not scarce; the ability to turn it into diesel and gasoline is."[\[2\]](https://app.hedgeye.com/insights/186113?ref=bushletter.com) That distinction matters. Releasing strategic crude reserves is the standard policy response to energy price spikes. It does almost nothing when the constraint is refining throughput rather than feedstock supply.

## What it costs Australia

Australia imports about 90 per cent of its refined fuel needs, including diesel.[\[3\]](https://www.minister.industry.gov.au/ministers/taylor/transcripts/interview-chris-smith-2gb-3?ref=bushletter.com) With so little diesel produced domestically, local prices are set by the international wholesale market and move with crack spreads, not just crude benchmarks. When crack spreads triple, the transmission to bowser prices and freight invoices is direct and fast.

Freight, mining and agriculture carry the most exposure, all running on diesel with no short-term substitute available. National Farmers' Federation president Hamish McIntyre said the pressure was already showing up in farm input costs. "We are already seeing signs of tightening supply and rising costs for key inputs. If farmers can't access reliable and affordable fuel and fertiliser, some may be forced to scale back plantings. That hits farm incomes, agricultural production and food availability."[\[4\]](https://nff.org.au/media-release/statement-on-ministerial-roundtable-on-fuel-supply-2/?ref=bushletter.com)

Australian grain growers are moving into a period of elevated diesel consumption for planting and harvest operations. Unlike mining companies, which can partially hedge fuel costs through financial instruments, most farm operations absorb price movements directly, and scaled-back plantings carry a second-order price effect that flows eventually to grocery shelves.

Russia's export suspension runs through January 2027, and Middle Eastern refinery restarts depend entirely on political and military developments that carry no reliable timeline.[\[2\]](https://app.hedgeye.com/insights/186113?ref=bushletter.com) The National Farmers' Federation's call for a ministerial roundtable on fuel supply was issued ahead of the Australian harvest season beginning in late 2026.[\[4\]](https://nff.org.au/media-release/statement-on-ministerial-roundtable-on-fuel-supply-2/?ref=bushletter.com)

This article contains analysis and commentary on market conditions. It does not constitute financial, investment, or professional advice. Past performance is not indicative of future results. Always consult a qualified adviser before making financial decisions.

SOURCES & CITATIONS

1. [US$100/bbl Diesel Crack: How 2026 Exposed Fragility in Global Refining](https://rbnenergy.com/daily-posts/blog/100bbl-diesel-crack-or-how-2026-exposed-fragility-global-refining?ref=bushletter.com)
2. [Hedgeye Risk Management: Diesel Crack Spread Analysis](https://app.hedgeye.com/insights/186113?ref=bushletter.com)
3. [Minister for Energy and Emissions Reduction interview, 2GB](https://www.minister.industry.gov.au/ministers/taylor/transcripts/interview-chris-smith-2gb-3?ref=bushletter.com)
4. [National Farmers' Federation: Statement on Ministerial Roundtable on Fuel Supply](https://nff.org.au/media-release/statement-on-ministerial-roundtable-on-fuel-supply-2/?ref=bushletter.com)

FREQUENTLY ASKED QUESTIONS

What is a diesel crack spread?

A crack spread is the difference between the wholesale price of a refined fuel product, such as diesel, and the cost of the crude oil used to produce it. It represents the refiner's gross margin per barrel. When crack spreads rise sharply, it signals a shortage of refining capacity rather than crude oil itself.

Why does Australia's diesel price track global refining margins so closely?

Australia imports about 90 per cent of its refined fuel needs, including diesel. Because so little diesel is produced domestically, local prices are set by the international wholesale market for refined products, which moves with crack spreads, not just crude oil benchmarks.

Why can't releasing strategic oil reserves fix this problem?

Strategic reserves hold crude oil, not refined diesel. The current shortage is in refining capacity, not feedstock supply. Adding more crude to a market already constrained by refinery outages does not increase the volume of diesel reaching consumers.

![Alex Mercer](https://res.cloudinary.com/dz77sb7j1/image/upload/v1774262566/bushletter/authors/alex-mercer.png)

[Alex Mercer](https://bushletter.com/author/alex-mercer/?ref=bushletter.com)

Alex Mercer writes about technology, energy and infrastructure. He likes the physical end of the story: the plants, the grids and the machines that everything else depends on.