Why is diesel so expensive right now?

The national terminal gate price for diesel was 264.9 c/L on 6 October 2026, 1.4 c/L below a week earlier. On the rule the site applies to petrol, the latest 5 trading days against the 5 before, wholesale diesel is easing (-2.2 per cent), and pump prices usually follow a wholesale move within one to two weeks.

Diesel never runs the discounting cycles that petrol does in the larger capitals, so there is no cheap end of a cycle to wait for and no retailer round to blame; the pump follows the terminal gate, with that lag.

On the official statement for 29 September 2026 Australia held 32 days of diesel cover, exactly on the 32-day line each importer is obliged to hold. The obligation is per importer rather than a national floor, and it has been under temporary relief since March, now extended to 31 January 2027, which lets suppliers hold less in return for committing to deliver more into the domestic market.

The National Fuel Security Plan sits at level 2 of 4, Keeping Australia moving, which the government describes as fuel continuing to flow with extra coordination and precautionary measures in place (fuelplan.gov.au, read 6 October 2026). The levels above it are Taking targeted action, then Protecting critical services for all Australians. Rationing is not a measure at the current level; what would move the level is the published days of cover, which this site reads every week on is there a fuel shortage? and the fuel supply page.

On 22 September 2026, asked at the United Nations about Republican calls for a ban on United States diesel exports, President Trump said he had called for one too, and on 23 September Semafor reported that the White House was preparing a plan for a 90-day ban. His own officials argued against it: the Energy Secretary, Chris Wright, said a ban was a blunt tool that definitely does not work, and the Treasury Secretary lobbied against it privately. No ban had been announced by 6 October. Australia buys little refined fuel directly from the United States, which sits inside the 3 per cent 'Other' row of the import table, so the exposure is to the international diesel benchmark that Australian importers pay rather than to cargoes.

The export curbs in China, South Korea, India and Thailand that bear on all refined fuel, and where Australia's diesel actually comes from, are on the supply and policy page.

Excise on diesel is the same 53.7 c/L as on petrol, and the temporary relief that ended in August applied to both fuels equally; no diesel-only relief exists. The stockholding obligation on importers is under relief to 31 January 2027. One fuel-quality setting touches diesel: Diesel minimum flash point held at 60.5 degrees C until 30 June 2027, which widens the pool of cargoes Australia can import while the strait is disrupted.

The excise arithmetic, the relief and the government's stated position on another cut are on the fuel excise page; the fuel-quality settings are on the supply and policy page.

Source: State government fuel price feeds, AIP terminal gate prices, DCCEEW stockholding statistics, ATO, fuelplan.gov.auUpdated 6 October 2026Pre-conflict retail levels petrol 171.0 c/L and diesel 180.2 c/L, AIP weekly reports, week ending 22 February 2026How we measure this

If a diesel figure on this page turns out to be wrong, the fix and a note of it go on the corrections page.