Price of petrol + Big Mac + Bank interest rate in Australia September 2026

Welcome to my updated monthly report on key financial figures for Australia. These are important to me but may offer some interest for you too. I am doing this to keep historical notes through my life. These figures reported are what I see at the various places and an aggregate.

The price of petrol I would have paid during September 2026 averaged $2.37 for unleaded 91 Octane. Add up to 15c for 95 or 25c for 98. The last price of diesel I saw was $ 2.85 per litre. Adblue  is still priced around $2 per litre. It’s relative of course due to fluctuation of supply due to the Iran war and shipping blockages. These are the highest prices I’ve seen for a little while. 

Note that in response the war and oil shortages the Australian federal and state governments have announced a reduction of the tax on fuel excise (effectively a tax) of 50% the rate 52.6 aka 26.3 cents and the state taxes of 5.7 cents. So the reduction is about 32 cents in total per litre. This expires on 30 June 2026. A second temporary discount of 16c per litre was applied from 1 July to the 2nd of August 2026. There are currently no plans to offer any further price relief.  

Following the developments during September 2026 market regarding tariffs : Tariffs are still definitely off the news cycles I write this due to new war against Iran but that does not make the problem go away.  Unfortunately the result has been reduced oil extraction, production, storage, shipping and uncertainty. Even Venezuela and Ukraine are long forgotten dramas. Although the tariffs where deemed illegal which shows the rule of law still works but there are many other issues which have made many countries reconsider their trading partners. The latest economic problem is the follow on effect of inflation relates to the increase in the Treasury Bond interest rates in particular the US which is tied directly to the Japanese interest rate via the carry trade. 

The price of a Big Mac in August 2026 averages $8.40. The price for the burger alone does vary from store to store based on location! This time it was the usual shopping centre location. The medium sized meal deal which included fries and a drink costs about $13.55 and the large option is still $14.45 as per my monthly visit. As always this is not a fixed price as McDonald’s has a very active app and promotional pricing and freebie schedule.

The RBA – Reverse Bank of Australia the country’s central bank increased the interest rate at 4.6 % 
The variable home loan interest rate range in August 2026 in Australia was : 5.95% – 9.3%
The saving interest rate range in August 2026 in Australia was : 0 – 6%
Note that the rates I saw came with conditions or short term promotion periods – very naughty. 

Note that fuel prices also vary according to area, the level of competition and a whole heap of other factors like shopping discounts, wars, world wide economics and so forth, however unreasonable high prices (relative to crude oil prices) is greed. Also note that the Octane level I post here represents Australian measurement which is different from those in other countries eg. US.

Apart from the actual prices I paid at the servo the websites I use to research the crude oil pricing are:

Australian Institute of Petroleum (Note that they AIP represents the oil companies.)
Index Mundi (Seems independent)