Australian diesel prices for mining: September 2026

On Friday 25 September 2026 the average diesel terminal gate price was 269.0 cents a litre nationally, including GST, ranging from 261.9 c/L in Perth to 277.6 c/L in Darwin. That is 24.9 c/L higher than a month earlier, on 25 August, according to the Australian Institute of Petroleum (AIP terminal gate prices and historical data file, read 25 Sep 2026).

September’s high so far was Tuesday 22 September, at a national average of 276.1 c/L, and the price eased on each of the next three days. After GST credits and the 53.7 c/L fuel tax credit, a GST-registered contractor running diesel off-road on a mine pays a net 184.4 c/L at the Perth terminal price and 198.7 c/L at the Darwin price, the lowest and highest capitals on 25 September.

Diesel terminal gate prices by capital city, 25 September 2026

The AIP publishes the average terminal gate price (TGP) across BP Australia, Ampol, Viva Energy Australia and ExxonMobil each weekday. An older AIP page describes the TGP as the “wholesale price for bulk purchase at the terminal” (AIP, TGP wholesale). All prices include GST.

Figures come from the AIP’s historical data file (AIP_TGP_Data, updated 25 September 2026). The 25 September city prices match the AIP’s web table, which does not show the national average. The change column is our subtraction of the published figures. The AIP computes its national average “as a weighted average of the city prices shown, based on volume sold in each State”.

Weekly averages in September

Each figure is our average of the five weekday prices the AIP published that week, in cents a litre including GST.

The national average rose by 36.5 c/L from the first week to the fourth. Perth had the lowest weekly average of the seven capitals in all four weeks and Darwin the highest. On 25 September the gap between them was 15.7 c/L. The steepest run came between 15 and 18 September, when the national price moved from 252.9 to 270.4 c/L.

Change on month

Averaged over the month, the national diesel TGP was 239.5 c/L in August 2026 (21 weekdays) and 254.7 c/L for 1 to 25 September (19 weekdays), a rise of 15.2 c/L. Perth averaged 234.8 c/L in August and 248.7 c/L so far in September.

August itself opened with a jump. The national average went from 224.4 c/L on Friday 31 July to 246.2 c/L on Monday 3 August, the day the ATO says “the temporary fuel excise relief has ended” (ATO fuel response). The July national average was 198.3 c/L. The AIP data do not give reasons for the September rise, so we do not offer one.

What fuel tax credits do to the net cost

Two things come off the terminal price for a GST-registered business burning diesel off-road on a mine.

• GST. GST is “a broad-based tax of 10%”, and registered businesses claim credits “for the GST included in the price of goods and services they buy for their business” (ATO, how GST works). The ex-GST price is the TGP divided by 1.1.
• Fuel tax credits. For diesel acquired from 3 August 2026, the credit is 53.7 c/L for off-road and other business uses and 21.3 c/L for heavy vehicles on public roads (ATO rates). Who can claim, and the records needed, are set out in fuel tax credits for mining contractors in Australia.

Net cost (c/L) = TGP including GST (c/L) / 1.1 - fuel tax credit (c/L)

Perth, 25 Sep 2026: 261.9 / 1.1 - 53.7 = 238.09 - 53.7 = 184.39 c/L

The fuel tax credit rate did not change during September, so the whole month’s rise in the terminal price reaches the net cost, less the GST share.

Diesel burned by a heavy vehicle travelling on a public road, such as a road train carting ore from the mine to a rail siding or port, earns the lower 21.3 c/L credit. At the Perth price of 25 September that leaves a net 216.8 c/L, against 184.4 c/L for the same litre used on the mine. The difference, 32.4 c/L, is the road user charge. Contractors running both kinds of work need to split their litres between the two rates, and the ATO expects records that show how the split was made (ATO, records you need to keep).

Worked example: per 1,000 litres and per tonne

A terminal gate price is a price at the terminal. What a remote mine pays is set by its supply agreement, so use these figures to track movement and compare cities.

About the AIP figures

The AIP’s daily table is prepared by ORIMA Research Pty Ltd “on behalf of the Australian Institute of Petroleum, using information provided by BP Australia, Ampol, Viva Energy Australia and ExxonMobil”. Prices “are generally collated each weekday morning”, and the data file has no weekend rows.

Three points to keep in mind when you use them:

• They are city prices. The table covers the seven capital city terminals. The AIP data we read do not give a figure for a regional or mine-site terminal.
• They include GST. Both the web table and the data file state that prices are inclusive of GST. The worked example above removes it before taking off the fuel tax credit.
• The national figure is weighted. The AIP weights it by the volume sold in each state, using Australian Petroleum Statistics.

We will update this series each month from the AIP data file and the ATO rate table in force on the day. If the ATO changes the fuel tax credit rate before the next indexation in February 2027, the net cost figures here will change with it.

Common questions

What is the diesel terminal gate price in Australia today?

On Friday 25 September 2026 the AIP average diesel terminal gate price was 269.0 cents a litre nationally, including GST. By city it ranged from 261.9 c/L in Perth to 277.6 c/L in Darwin.

How much did diesel rise in September 2026?

The national average terminal gate price rose 24.9 c/L between 25 August and 25 September 2026, from 244.1 to 269.0 c/L. The average for 1 to 25 September was 254.7 c/L, against 239.5 c/L for August.

What does diesel cost a mine site after fuel tax credits?

At the Perth price of 261.9 c/L on 25 September, a GST-registered business using the diesel off-road pays about 184.4 c/L net: 238.1 c/L excluding GST, less the 53.7 c/L fuel tax credit. Delivery and supply terms come on top.

Do AIP terminal gate prices include GST?

Yes. The AIP publishes diesel terminal gate prices in cents per litre inclusive of GST. A GST-registered business can divide by 1.1 to get the price before GST, which is the figure fuel tax credits come off.

Sources

1. Terminal Gate Prices, Australian Institute of Petroleum, daily table for 21 to 25 September 2026.
2. Historical ULP and diesel TGP data, Australian Institute of Petroleum, AIP_TGP_Data updated 25 September 2026.
3. Terminal Gate Prices (wholesale), Australian Institute of Petroleum.
4. Fuel tax credit rates: from 1 July 2026 to 30 June 2027, ATO.
5. ATO fuel response, ATO.
6. How GST works, ATO.
7. Records you need to keep, ATO.